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THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epitror: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Prorrssors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M..DAVIS, or Camsrines, 


Prorsssors A. E. VERRILL, HORACE L. WELLS, CHARLES 
SCHUCHERT, L. V. PIRSSON, H. E. GREGORY, 
anp HORACE 8S. UHLER, or New Haven, 


Proressor JOSEPH S. AMES, or Battimorz, 
Mr. J. 8S. DILLER, or Wasurneron. 


FOURTH SERIES 
VOL. XLVI-[WHOLE NUMBER, CXCVT}. 


WITH TWO PLATES 
“3 $2204 
NEW HAVEN, CONNECTICUT. 


1918. 


THE TUTTLE, MOREHOUSE & TAYLOR COMPANY 
A NEW HAVEN 


CONTENTS TO VOLUME XLVI. 


Number 271. 


Art. I.—The American Journal of Science from 1818 to 1918; 
PR RErEVeRo. D) ANAND Te ee 


Il.—A Century of Geology, 1818-1918: Historical Geology; 
By OuAREWs OCHUCHHRT 5. 22200522220 Sse 


Ill.—A Century of Geology: Steps of Progress in the Inter- 
pretation of Land Forms; by Hrerpert EK. Grecory.-. - 


IV.—A Century of Geology: The Growth of Knowledge of 
Harth Structure; by JosrpH BaRRELL.-.--..---------- 


V.—A Century of Government Geological Surveys; by 
Sew Ore EROS MSO MIE Hg foo) sa ee ek 


ViI—The Development of Vertebrate Pe ORY = by 
PP EO AEE Se. eae ead. tine. of Sone es 


VII.—The Rise of Perle: as a Science; by Louis V. 


> LUSSIE Vice PRene Se OO Be ae Oe eS Spake eather ea iiryatiy 


VIIl.—The Growth of Mineralogy from 1818 to 1918; by 
Bibeeimone ORD: ne eee Se Ce ete A 


VItIa.—The Work of the Geophysical Laboratory of the 
Carnegie Institution of Washington; by R. B. Sosman- 


IX.—The Progress of Chemistry during the past One Hun- 
dred Years; by H. L. Wetts and H. W. Foors.----.- 


X.—A Century’s Progress in Physics; by Letau PacsE.---- 
RES A Century of Zoology in America; by Wers.LEy R. Cor 


XIJ.—The Development of Botany as shown in this Journal; 
PmerEOR GH WG OOM MLE soba 6 an ale 


ERRATA. 


Page 34, line 10 (bottom), for 27, 40b, 1835, read 27, 406, 1835: 


Page 


Page 37, line 3 (bottom), also page 40, line 8, for George W. read George 


Is Goodale. 
Page 38, line 9, for 35, 181, 1855, read 35, 181, 1888. 


Page 10 near bottom, after 1818, American Journal etc., add the line : 
1818—. Flora, or Allgemeine botanische Zeitung. Regensburg, Munich. 


lv CONTENTS. 


Number 272. 


Page 
Art. XIIL.—The Melting Points of Cristobalite and Tridy- | 
mite; by J. B. Fercuson and H. E, Merwin .-..---_- 417 
XIV.—The Application of Rapidly Rotating Metallic Re- 
ductors in the Determination of Vanadie Acid; by F. A. 
Goocna and W .Scotr :..-.-.- -2. 522 42/7 
XV.—Notes on the Geology of Rhode Island; by A. C. 
HAWEING 22... .+..2-+-)-75 Upp Ss S255 e ee rn 437 
XVI—A Possible Source of Vanadium in Sedimentary 
Rocks; by, A. H..Paiibs...-....- 4. 9. ae 


Geology and Mineralogy—Fossil Plants: a text-book for students of Botany 
and Geology, A. C. SEwarp, 475.—The Cedar Mountain Tiap Ridge near 
Hartford, W. M. Davis. 476.—Canada Department of Mines, 477.—Con- 
tributions to the Mineralogy of Black Lake Area, Quebec, E. Porrrvin 
and R. P. D. Granaw, 479. 


Miscellaneous Scientific Intelligence—Field Museum of Natural History, F. J. 
V. Sxirr: The Sarawak Museum Journal, 479.—The Normal and Patho- 
logical Histology of the Mouth, A. HopsweELu-SmitH: Helvetica Chimica 
Acta, 480. Pg 


Obituary—W. EK. Hippen: A. PepuEr, 480. 


CONTENTS. ¥ 


Number 278. 


Page 
Arr XVII.—A Modification of the Periodic Table; by I. 
Per rere eee. ie i et sl it a8 
XVIII—On the Cretaceous Age of the “ Miocene Flora” of 
Sendai: soy A. N. KRryvsHTOFOVICH,.. 2. .2.. 2.2. -. . 502 
XIX.—Paleozoic Glaciation in Southeastern Alaska; by E. 
OS TETE. Layee LS a a a sae pe ree Re Ne eg Dee” ee Aree 511 
XX.—The Lopolith; an Igneous Form Exemplified by the 
Mami Gabbro; by. Hy KF: Grout): 3. 22 a26 ses! pak 516 
XX1i.—Geologic Section of Blair and Huntingdon Counties, 
Sentral Pennsylvania; by .C. Burrs 22 22.2: 22h. 2522 528 


XXIU.—A Method for the Separation and Determination of 
Barium Associated with Strontium; by F. A. Goocu 
AE OMEENAN so ee ee eS 538 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Modern Inorganic Chemistry, J. W. MELLOR: 
James Woodhouse, a pioneer in Chemistry, 1770-1809, E. F. Smirx, 541.— 
Laboratory Manual, A. A. BLANCHARD and F. B. WabeE: Lessons in 
Astronomy, Revised Edition. C. A. Youne: The Origin of our Planetary 
System, E. Miter, 542.—Ozone, and the Ultra-violet Transparency of 
the Lower Atmosphere, R. J. Strutt, 543.—Molecular Frequency and 
Molecular Number, H. S. ALLEN, 544. 


Geology—Thirteenth Report of the Director of the State Museum and Science 
Department, State of New York, J. M. CLarKE, 545.—Geology of the 
Oregon Cascades, W. Du Pre Smits: Evolution of Vertebrze, and The 
Osteology of some American Permian Vertebrates, III, S. W. WiL.iston, 
546 —Onaping Map-area, W. H. CoLuins: Timiskaming County, Quebec, 
M. E. Witson: The Pliocene History of Northern and Central Mississippi, 
E. W. Suaw, 547. 


Miscellaneous Scientific Intelligencc—Chemistry of Food and Nutrition, H. C. 
SHERMAN: Physical Chemistry of the Proteins, T. B. Ropertson, 548.— 
Lecithin and Allied Substances, The Lipins, H. Macnizeaw: Directions for 
a Practical Course in Chemical Physiology, W. CRAMER: An Outline of the 
History of Phytopathology, H. H. Wuetzet, 549. 


Obituary—H. S. Wiuxiams: J. D. Irvine: C. C. TROWBRIDGE, 550. 


v1 CONTENTS. 


Number 274. 
Art. XXIIJ.—The Green River Desert Section, Utah; by 
W. B. EMsRY 2.2.2.0... =e ee 551 
XXIV.—The Law of Dissipation of Motion; by E. Jonson. 578 


XX V.—An American Occurrence of Periclase and its Bear- 
ing on the Origin and History of Calcite-Brucite Rocks; 


Page 


by A. FF. Rogers. .2.... 2.222 5s a 581 
XXVI.— On the Preparation of Hypophosphates; by R. G. 
VanName and W. J. Horr: 2... _2. 22 ee 587 
XX VII.—Origin of the Western Phosphates of the United 
States; by G. R. Mansrikip. ge. 232). eee 591 
XXVIII. — Dustfall of March 9, 1918; by A. N. WincHELi 
and EH. BR. Minter 222.0222 22. 2 ee 
XXIX.—Note on a Universal Switch for Delicate Potential 
Measurements ; by W. P. Wsitm. = 2.252583 610 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Apparatus for Determining Molecular Weights and 
Hydrogen Equivalents, W. H. Cuaapin, 613.—Detection of Iodides in the 
Presence of Cyanides, L. J. CuRTMAN and C. Kaurman: Determination of 
Zine as Zine Mercury Thiocyanate, G. S. Jamieson: Principles of Chem- 
istry, J. H. HILLEBRAND, 614.—Organic Compounds of Arsenic and Anti- 
mony, G. T. Morean: Edible Oils and Fats, C. A. MitcHELL: Seattering 
of Light by Dust-free Air, with Artificial Reproduction of the Blue Sky, 
R. J. Strutt, 615.—Occurrence in the Solar Spectrum of the Ultra-violet 
Bands of Ammonia and of Water-vapor, A. FowLer and C. C. L. GREGORY, 
617.—A Calendar of Leading Experiments, W. S. FRANKLIN and B. Mac 
Nort, Gis. 


Miscellaneous Scientific Intelligence—Journal of the Ceramic Society, 619.— 
A Century of Science in America with especial reference to the American 
Journal of Science, 1818-1918, 620. 


Obituary—R. Ratusun: S. F. Peckaam: S. W. WIL.isron, 620. 


CONTENTS. Vil 


Number 275. 


Page 
Art. XX X.—Radioactive Properties of the Mineral Springs 
Geeeolowdo;. by.OnC) Luspmr ui foe set ig ee ec ent 621 
XXXI.—Spotted Lakes of Epsomite in Washington and 
Buch: Columbia ; iby O;P. Penkine? 222055 -2--<265 638 
XX XIL—A Study of Some American Fossil Cycads ; Part 
VIII, Notes on Young Floral Structures; by G. R. 
PeMULTO Nie temo TE ee Se Ue eee el BED 
XXXIII.—Means of Solving Crystal Problems; by J. M. 
AR a 0s ie eee eS ed Se 651 
XXXIV.—Separation of Germanium from Arsenic by the 
Distillation of the Chloride in the Presence of a Chro- 
mate; by P. E. Brownine and 8. E. Scotr.-.-------- 663 
XXXV.—Mysticocrinus, a new genus of Silurian Crinoidea; 
Buel eDERINGHE (With Plate Il). 22.2702. 222 666 
Been MnORE GIGRERT,. 2205 oo. tee een Ja HS. B69 


PMEMEE STAT HR VV TELIAMS...-. 20.2 20 ft eee 682 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—A New Method for the Quantitative Estimation of 
Vapors in Gases, H. S. Davis and Mary D. Davis: Determination of Or- 
ganic Matter in Soils, J B. Ratuer, 688.—A New Reaction for Osmium, M. 
T. TScCHUGAEFF: Chemical Combinations among Metals, M. G. and CLARA 
Giua-Louuini: The Zinc Industry, E. A. SMirH: Stoichiometry, S. YounG, 
689.—Elements of General Science, Revised Edition, O. W. CADWELL and 
W. E. E1kenBerry, 690.—Airplane Characteristics, F. BEDELL, 691. 


Miscellaneous Scientific Intelligence—Medical Contributions to the Study of 
Evolution, J. G. Apami, 691. 


Obituary—C. R. Hastman: W. B. Paruuirs, 692. 


M1] CONTENTS. 


Number 276. 


Page 
Art. XXXVI.—The Origin of Serpentine, a Historical and 
Comparative Study; by W. N. Benson...--.--_.._-- 693 
ArT. XXXVII.—Stratigraphy and Correlation ot the Devo- 
nian of Western Tennessee; by C. O. DunBar___-.... 732 
RicwarpD Ratusun and His Contributions to Zoology -.-.-, 757 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—N otes on Isotopic Lead, F. W. CLARKE: Recovery of 
Potash and Other Materials from Kelp, C. A. Hiaeins, 764.—Treatise on 
Applied Analytical Chemistry, V. VILLAVaccHtIa: Outlines of Theoreti- 
cal Chemistry. F. H. German, 765 —Electro-Analysis, E. F. SmirH: 
Absorption of X-Rays in Aluminium and Copper, C. M. WiLLiams, 766. 
—Flame and Furnace Spectra of Iron, G. A. HEMSALECH, 767.—Pub- 
lications of the American Astronomical Society, 768. 


Geology —Maryland Geological Survey, E. B. MatnEews, 768.—San Lorenzo 
Series of Middle Califurnia, B. L. Chark: West Virginia Geological 
Survey, I. C. Wuartr. 769. -The Evolution of the Earth and its Inhabi- 
tants. J. BARRELL, C. Scoucuert, L. L. Wooprvurr, R. S. LULL, and 
K. HUNTINGTON: Equide of the Oligocene, Miocene, and Pliocene of 
North America, Ilconographie type revision, H. F. Osporn, 770.—The 
genus Homalonotus, F. R. C. REeEp, 771. 

Miscellaneous Scientific Intelligence—Dispensaries, their Management and 
Development. M. M. Davis, Jr., and A. R. Warner, 771.—Principles 


and Practice of Filling Teeth, C. N. Jonnson: A Study of Engineering 
Edueation, C. R. Mann: National Academy of Sciences, 772. - 


Inprex to Volume XLVI, 773. 


$s 
SR 


eee pone 


BENJAMIN SILLIMAN, M.D., LL.D. 


PROFESSOR OF CHEMISTRY, PHARMACY, MINERALOGY 
AND GEOLOGY 


IN YALE COLLEGE 


PREFATORY NOTE 


The present number commemorates the one-hundredth anni- 
versary of the founding of the American Journal of Science by 
Benjamin Silliman in July, 1818. The opening chapter gives 
a somewhat detailed account of the early days of the Journal, 
with a sketch of its subsequent history. The remaining chap- 
ters, eleven in number, are devoted to the principal branches of 
science which have been prominent in the pages of the Journal. 
They have been written with a view to showing in each case 
the position of the science in 1818 and the general progress made 
during the century; special prominence is given to American 
science and particularly to the contributions to it to be found 
in the Journal’s pages. References to specific papers in the 
Journal are in most cases included in the text and give simply 
volume, page, and date, as (24, 105, 1833); when these and 
other references are in considerable number they have been 
brought together as a Bibliography at the end of the chapter. 

The entire cost of the present number is defrayed from the 
income of the Mrs. Hepsa Ely Silliman Memorial Fund, estab- 
lished under the will of Augustus Ely Silliman, a nephew of 
Benjamin Silliman, who died in 1884. Certain of the chapters 
here printed have been made the basis of a series of seven Silli- 
man Lectures in accordance with the terms of that gift. The 
selection of these lectures has been determined by the conveni- 
ence of the gentlemen concerned and in part also by the nature 
of the subject. A special volume reproducing this number, with 
some important additions, will soon be published by the Yale 
University Press. 


AMERICAN JOURNAL OF > SCIENCE 


[FOURTH SERIES.] 


oe 


Art. L—The American Journal of Science from 1818 
to 1918; by Epwarp 8. Dana. 


INTRODUCTION. 


In July, 1818, one hundred years ago, the first number 
of the American Journal of Science and Arts was given 
to the public. This is the only scientific periodical in this 
country to maintain an uninterrupted existence since that 
early date, and this honor is shared with hardly more 
than half a dozen other independent scientific periodicals 
in the world at large. Similar publications of learned 
societies for the same period are also very few in number. 

It is interesting, on the occasion of this centenary, to 
glance back at the position of science and scientific liter- 
ature in the world’s intellectual life in the early part of 
the nineteenth century, and to consider briefly the mar- 
velous record of combined scientific and industrial prog- 
ress of the hundred years following—subjects to be 
handled in detail in the succeeding chapters. It is fitting 
also that we should recall the man who founded this 
Journal, the conditions under which he worked, and the 
difficulties he encountered. Finally, we must review, but 
more briefly, the subsequent history of what has so often 
been called after its founder, ‘‘Silliman’s Journal.’’ 

The nineteenth century, and particularly the hundred 
years in which we are now interested, must always stand 
out in the history of the world as the period which has 
combined the greatest development in all departments of 
science with the most extraordinary industrial progress. 
It was not until this century that scientific investigation 


Am. Jour. Sci.—Fourta SerRIES, Vout. XLVI, No. 271.—Juty, 1918. 
a! 


2 Dana—American Journal of Science, 1818-1918. 


used to their full extent the twin methods of observation 
and experiment. In cases too numerous to mention they 
have given us first, a tentative hypothesis; then, through 
the testing and correcting of the hypothesis by newly 
acquired data, an accepted theory has been arrived at; 
finally, by the same means carried further has been 
established one of nature’s laws. 

Early Science.—Looking far back into the past, it 
seems surprising that science should have had so late a 
growth, but the wonderful record of man’s genius in the 
monuments he erected and in architectural remains 
shows that the working of the human mind found expres- 
sion first in art and further man also turned to litera- 
ture. So far as man’s thought was constructive, the 
early results were systems of philosophy, and explana- 
tions of the order of things as seen from within, not as 
shown by nature herself. We date the real beginning of 
science with the Greeks, but it was the century that pre- 
ceded Aristotle that saw the building of the Parthenon 
and the sculptures of Phidias. Even the great Aristotle 
himself (384-322 B. C.) though he is sometimes called the 
‘‘founder of natural history,’’ was justly accused by 
Lord Bacon many centuries later of having formed his 
theories first and then to have forced the facts to agree 
with them. 

The bringing together of facts through observation 
alone began, to be sure, very early, for it was the motion 
of the sun, moon, and stars and the relation of the earth 
to them that first excited interest, and, especially in the 
countries of the East, led to the accumulation of data as 
to the motion of the planets, of comets and the occur- 
rence of eclipses. But there was no coordination of 
these facts and they were so involved in man’s super- 
stition as to be of little value. In passing, however, it is 
worthy of mention that the Chinese astronomical data 
accumulated more than two thousand years before the 
Christian era have in trained hands yielded results of no 
small significance. 

Doubtless were full knowledge available as to the 
science existing in the early civilizations, we should rate 
it higher than we can at present, but it would probably 
prove even then to have been developed from within, like 
the philosophies of the Greeks, and with but minor 
influence from nature herself. It is indeed remarkable 


Dana—American Journal of Science, 1818-1918. 3 


that down to the time with which we are immediately con- 
cerned, it was the branches of mathematics, as arithmetic 
and geometry and later their applications, that were first 
and most fully developed: in other words those lines of 
science least closely connected with nature. 

Of the importance to science of the Greek school at 
Alexandria in the second and third centuries B. C., there 
ean be no question. The geometry of Euclid (about 300 
B. C.) was marvelous in its completeness as in clearness 
of logical method. Hipparchus (about 160-125 B. C.) 
gave the world the elements of trigonometry and devel- 
oped astronomy so that Ptolemy 260 years later was able 
to construct a system that was well-developed, though in 
error in the fundamental idea as to the relative position 
of the earth. It is interesting to note that the Almagest 
of Ptolemy was thought worthy of republication by the 
Carnegie Institution only a year or two since. This 
great astronomical work, by the way, had no successor 
till that of the Arab Ulugh Bey in the fifteenth century, 
which within a few months has also been made available 
by the same Institution. 

To the Alexandrian school also belongs USrohimesie: 
(287-212 B. C.), who, as every school boy knows, was the 
founder of mechanics and in fact almost a modern physi- 
cal experimenter. He invented the water screw for rais- 
ing water; he discovered the principle of the lever, 
which appealed so keenly to his imagination that he 
called for a zov oro, or fulerum, on which to place it so as 
to move the earth itself. He was still nearer to modern 
physics in his reputed plan of burning up a hostile fleet 
by converging the sun’s rays by a system of great 
mirrors. 

To the Romans, science owes little beyond what is 
implied in their vast architectural monuments, buildings 
and aqueducts which were erected at home and in the 
countries of their conquests. The elder Pliny (23-79 
A. D.) most nearly deserved to be called a man of science, 
but his work on natural history, comprised in thirty- 
seven volumes, is hardly more than a compilation of 
fable, fact, and fancy, and is sometimes termed a collec- 
tion of anecdotes. He lost his life in the ‘‘grandest 
geological event of antiquity,’’ the eruption of Vesuvius, 
which is vividly described by his nephew, the younger 


4. Dana—American Journal of Science, 1818-1918. 
Pliny, in ‘‘one of the most remarkable literary produc- 
tions in the domain of geology’’ (Zittel). 

With the fall of Rome and the decline of Roman civ- 
ilization came a period of intellectual darkness, from 
which the world did not emerge until the revival of learn- 
ing in the fifteenth and sixteenth centuries. Then the 
extension of geographical knowledge went hand in hand 
with the development of art, literature, and the birth of a 
new science. Copernicus (147 3-1543) gave the world at 
last a sun-controlled solar system; Kepler (1571-1630) 
formulated the laws governing the motion of the planets ; 
Galileo (1564-1642) with his telescope opened up new 
vistas of astronomical knowledge and laid the founda- 
tions of mechanics; while Leonardo da Vinei (1452-1519), 
painter, sculptor, architect, engineer, musician and true 
scientist, studied the laws of falling bodies and solved — 
the riddle of the fossils in the rocks. Still later Newton 
(1642-1727) established the law of gravitation, developed 
the caleulus, put mechanics upon a solid basis and also 
worked out the properties of lenses and prisms so that 
his Optics (1704) will always have a pRaie place in 
the history of science. 

From the time of the Renaissance on science grew 
steadily, but it was not till the latter half of the eight- 
eenth century that the foundations in most of the lines 
recognized to-day were fully laid. Much of what was 
accomplished then is, at least, outlined in the chapters 
following. 

Our standpoint in the early vears of the nineteenth 
century, just before the American Journal had its begin- 
ning, may be briefly summarized as follows: A desire 
for knowledge was almost universal and, therefore, also 
a general interest in the development of science. Mathe- 
matics was firmly established and the mathematical side 
of astronomy and natural philosophy—as physics was 
then called—was well developed. Many of the phenom- 
ena of heat and their applications, as in the steam engine 
of Watt, were known and even the true nature of heat had 
been almost established by our countryman, Count Rum- 
ford; but of electricity there were only a few sparks of 
knowledge. Chemistry had had its foundation firmly 
laid by Priestley, Lavoisier, and Dalton, while Berzelius 
was pushing rapidly forward. Geology had also its 
roots down, chiefly through the work of Hutton and 


Dana—American Journal of Science, 1818-1918. 5 


William Smith, though the earth was as yet essentially 
an unexplored field. Systematic zoology and botany had 
been firmly grounded by Buffon, Lamarck and Cuvier, on 
the one hand, and Linneus on the other; but of all that is 
embraced under the biology of the latter half of the 
nineteenth century the world knew nothing. The state- 
ments of Silliman in his Introductory Remarks in the 
first number, quoted in part on a following page, put 
the matter still more fully, but they are influenced by the 
enthusiasm of the time and he could have had little com- 
prehension of what was to be the record of the next one 
hundred years. 

Now, leaving this hasty and incomplete retrospect and 
coming down to 1918, we find the contrast between to-day 
and 1818 perhaps most strikingly brought out, on the 
material side, if we consider the ability of man, in the 
early part of the nineteenth century, to meet the demands 
upon him in the matter of transportation of himself and 
his property. In 1800, he had hardly advanced beyond 
his ancestor of the earliest civilization; on the contrary, 
he was still dependent for transportation on land upon 
the muscular efforts of himself and domesticated ani- 
mals, while at sea he had only the use of sails in addition. 
The first application of the steam engine with commercial 
success was made by Fulton when, in 1807, the steamboat 
‘‘Clermont’’ made its famous trip on the Hudson River. 
Since then, step by step, transportation has been made 
more and more rapid, economical and convenient, both on 
land and water. This has come first through the per- 
fection of the steam engine; later through the agency of 
electricity, and still further and more universally by the 
use of gasolene motors. Finally, in these early years of 
the twentieth century, what seemed once a wild dream of 
the imagination has been realized, and man has gained 
the conquest of the air; while the perfection of the sub- 
marine is as wonderful as its work can be deadly. 

Hardly less marvelous is the practical annihilation of 
space and time in the electric transmission of human 
thought and speech by wire and by ether waves. While, 
still further, the same electrical current now gives man 
his artificial illumination and serves him in a thousand 
ways besides. 

But the limitations of space have also been conquered, 
during the same period, by the spectroscope which brings 


6 Dana—Aierican Journal of Science, 1818-1918. 


a knowledge of the material nature of the sun and the 
fixed stars and of their motion in the line of sight; while 
spectrum analysis has revealed the existence of many 
new elements and opened up vistas as to the nature of 
matter. 

The chemist and the physicist, often working together 
in the investigation of the problems lying between their 
two departments, have accumulated a staggering array 
of new facts from which the principles of their sciences 
‘ have been deduced. Many new elements have been dis- 
covered, in fact nearly all called for by the periodic law; | 
the so-called fixed gases have been liquefied, and now air 
in liquid form is almost a plaything; the absolute zero 
has been nearly reached in the boiling point of helium; 
physical measurements in great precision have been car- 
ried out in both directions for temperatures far beyond 
any scale that was early conceived possible; the atom, 
once supposed to be indivisible, has been shown to be made 
up of the much smaller electrons, while its disintegration 
in radium and its derivatives has been traced out and 
with consequences only as yet partly understood but cer- 
tainly having far-reaching consequences; at one point 
we seem to be brought near to the transmutation of the 
elements which was so long the dream of the alchemist. 
Still again photography has been discovered and per- 
fected and with the use of X-rays it gives a picture of the 
structure of bodies totally opaque to the eye; the same 
X-rays seem likely to locate and determine the atoms in 
the crystal. 

Here and at many other points we are reaching out to 
a knowledge of the ultimate nature of matter. 

In geology, vast progress has been made in the 
knowledge of the earth, not only as to its features now 
exhibited at or near the surface, but also as to its history 
in past ages, of the development of its structure, the 
minute history of its life, the phenomena of its earth- 
quakes, voleanoes, ete. Geological s surveys in all civilized 
countries have been carried to a high degree of per- 
fection. | 

In biology, itself a word which though used by 
Lamarck did not come into use till taken up by Huxley, 
and then by Herbert Spencer in the middle of the cen- 
tury, the progress is no less remarkable as is well devel- 
oped in a later chapter of this number. 


Dana—American Journal of Science, 1818-1918. 7 


Although not falling within our sphere, it would be 
wrong, too, not to recognize also the growth of medicine, 
especially through the knowledge of bacteria and their 
functions, and of disease germs and the methods of com- 
bating them. The world can never forget the debt it 
owes to Pasteur and Lister and many later investigators 
in this field. 

To follow out this subject further would be to encroach 
upon the field of the chapters following, but, more 
important and fundamental still than all the facts dis- 
covered and the phenomena investigated has been the 
establishment of certain broad scientific principles which 
have revolutionized modern thought and shown the rela- 
tion between sciences seemingly independent. The law 
of conservation of energy in the physical world and the 
principle of material and organic evolution may well be 
said to be the greatest generalizations of the human 
mind. Although suggestions in regard to them, particu- 
larly the latter, are to be found in the writings of early 
authors, the establishment and general acceptance of 
these principles belong properly to the middle of the 
nineteenth century. They stand as the crowning achieve- 
ment of the scientific thought of the period in which we 
are interested. 

Any mere enumeration of the vast fund of knowledge 
accumulated by the efforts of man through observation 
and experiment in the period in which we are interested 
would be a dry summary, and yet would give some meas- 
ure of what this marvelous period has accomplished. As 
in geography, man’s energy has in recent years removed 
the reproach of. a ‘‘Dark Continent,’’ of ‘‘unexplored’’ 
central Asia and the once ‘‘inaccessible polar regions,’’ 
so in the different departments of science, he has opened 
up many unknown fields and accumulated vast stores of 
knowledge. It might even seem as if the limit of the 
unknown were being approached. There remains, how- 
ever, this difference in the analogy, that in science the 
fundamental relations—as, for example, the nature of 
gravitation, of matter, of energy, of electricity; the 
actual nature and source of life—the solution of these 
and other similar problems still lies in the future. What 
the result of continued research may be no one ean pre- 
dict, but even with these possibilities before us, it is 
hardly rash to say that so great a combined progress of 


8 Dana—American Journal of Scrence, 1818-1918. 


pure and applied science as that of the past hundred 
years is not likely to be again realized. 


SCIENTIFIC PERIODICAL LITERATURE IN 1818. 


The contrast in scientific activity between 1818 and 
1918 is nowhere more strikingly shown than in the 
amount of scientific periodical literature of the two 
periods. Of the thousands of scientific journals and reg- 
ular publications by scientific societies and academies 
to-day, but a very small number have carried on a con- 
tinuous and practically unbroken existence since 1818. 
This small amount of periodical scientific literature in 
the early part of the last century is significant as giving 
a fair indication of the very limited extent to which 
scientific investigation appealed to the intellectual life of 
the time. Some definite facts in regard te the scientific 
publications of those early days seem to be called for. 

Learned societies and academies, devoted to literature 
and science, were formed very early but at first for occa- 
sional meetings only and regular publications were in 
most eases not begun till a very much later date. Some 
of the earliest—not to go back of the Renaissance—are 
the following: 


1560. Naples, Academia Secretorum Nature. 

1603. Rome, Accademia dei Lineei. 

1651. Leipzig, Academia Nature Curiosum. 

1657. Florence, Accademia del Cimento. 

1662. London, Royal Society. 

1666. Paris, Académie des Sciences. 

1690. Bologna, Accademia delle Scienze. 

1700. Berlin, Societas Regia Scientiarum. This was the 
forerunner of the K. preuss. Akad. d. Wissenschaften. 


The Royal Society of London, whose existence dates 
from 1645, though not definitely chartered until 1662, 
began the publication of its ‘‘Philosophical Transac- 
tions’’ in 1665 and has continued it practically unbroken 
to the present time; this is a unique record. Following 
this, other early—but in most cases not continuous— 
publications were those of Paris (1699); Berlin (1710) ; 
Upsala (1720); Petrograd, 1728; . Stockholm, (1739); 
and Copenhagen (1743). 

For the latter half of the eighteenth century, when the 
foundations of our modern science were being rapidly 


Dana—American Journal of Science, 1818-1918. 9 


laid, a considerable list might be given of early publica- 
tions of similar scientific bodies. Some of the prominent 
ones are: Gottingen (1750), Munich (1759), Brussels 
(1769), Prague (1775), Turin (1784), Dublin (1788), ete. 
The early years of the nineteenth century saw the begin- 
nines of many others, particularly in northern Italy. It 
is to be noted that, as stated, only rarely were the publi- 
cations of these learned societies even approximately 
continuous. In the majority of cases the issue of trans- 
actions or proceedings was highly irregular and often 
interrupted. 

In this country the earliest scientific bodies are the 
following: 

Philadelphia. American Philosophical Society, founded in 
1743. Transactions were published 1771-1809; then inter- 
rupted until 1818 et seq. 

Boston. American Academy of Arts and Sciences, founded 
in 1780. Memoirs, 1785-1821; and then 1833 e7 seq. 

New Haven. Connecticut Academy of Arts and Sciences, 
begun in 1799. Memoirs, vol. 1, 1810-16; Transactions, 1866 
et seq. 

Philadelphia. Academy of Natural Sciences, begun in 1812. 
Journal, 1817-1842; and from 1847 et seq. 

New York. Lyceum of Natural History, 1817; later (1876) 
became the New York Academy of Sciences. Annals from 1823; 
Proceedings from 1870. 


The situation is somewhat similar as to independent 
scientific journals. A list of the names of those started 
only to find an early death would be a very long one, but 
interesting only historically and as showing a spasmodic 
but unsustained striving after scientific growth. 

Jt seems worth while, however, to give here the names 
of the periodicals embracing one or more of the sub- 
jects of the American Journal, which began at a very 
early date and most of which have maintained an unin- 
terrupted existence down to 1915. It should be added 
that certain medical journals, not listed here, have also 
had a long and continued existence." 

1The statements given are necessarily much condensed, without an 
attempt to follow all changes of title; furthermore, the dates of actual 
publication for the academies given above are often somewhat vaguely 
recorded. For fuller information see Scudder’s ‘‘Catalogue of Scientific 
Serials, 1633-1876,’’ Cambridge, 1876; also H. Carrington Bolton’s 
“*Catalogue of Scientific and Technical Periodicals, 1665-1882’? (Smith- 


sonian Institution, 1885). The writer is much indebted to Mr. C. J. Barr 
of the Yale University for his valuable assistance in this connection. 


10 Dana—American Journal of Scrence, 1818-1918. 


Early Scientific Journals. 


1771-1823. Journal de Physique, Paris; title changed several 
times. 

1787-. Botanical Magazine. (For a time known as Curtis’s 
Journal. ) 

1789-1816. Annales de Chimie, Paris. Continued from 1817 
on as the Annales de Chimie et de Physique. 

1790. Journal der Physik, Halle (by Gren); from 1799 on 
became the Annalen der Physik (und Chemie), Halle, Leipzig. 
The title has been somewhat changed from time to time though 
publication has been continuous. Often referred to by the name 
of the editor-in-chief, as Gren, Gilbert, Poggendorff, Wiedemann, 
ete: 

1795-1815. Journal des Mines, Paris, continued from 1816 
as the Annales des Mines. 

1796-1815. Bibliotheque Britannique, Geneva. From 1816— 
1840, Biblhothéque Universelle, ete. 1846-1857, Archives des 
Sci. phys. nat. Since 1858 generally known as the Bibliothéque 
Universelle. 

1797. Journal of Natural Philosophy, Chemistry and the 
Arts (Nicholson’s Journal) London; united in 1814 with the 
Philosophical Magazine (Tuilloch’s Journal). 

1798—. The Philosophical Magazine (originally by Tulloch). 
This absorbed Nicholson’s Journal (above) in 1814; also the 
Annals of Philosophy (Thomson, Phillips) in 1827 and Brew- 
sters’ Edinburgh Journal of Science in 1832. | 

1798-1803. Allgemeines Journal de Chemie (Scherer’s 
Journal). 1803-1806; continued as Neues Allg. J. ete. (Geh- 
len’s Journal.) Later title repeatedly changed and finally 
(1834 et seq.) Journal fir praktische Chemie. 

1816-18. Journal of Science and the Arts, London. 1819-— 
30, Quarterly J. ete. 1830-31, Journal of the Royal Institution 
of Great Britain. : 


1818. American Journal of Science and Arts until 1880, 
when ‘‘the Arts’’ was dropped, New Haven, Conn. First 


Series, 1-50, 1818-1845; Second Series, 1-50, 1846-1870; Third 
Series, 1-50, 1871-1895; Fourth Series, 1-45, 1896-June, 1918. 


1820-1867. London Journal of Arts and Seiences Be 
1855, Newton’s Journal). 

1824. Annales des sciences naturelles. Paris. 

1826—. Linnea, Berlin, Halle; from 1882 united with Jahrb. 
d. K. botan. Gartens. 

1828-1840. Magazine of Natural History, London; united 
1838 with the Annals of Natural History, and known since 1841 
as the Annals and Magazine of Natural History. 


Dana—American Journal of Science, 1818-1918. 11 


1828-. Journal of the Franklin Institute, Philadelphia, from 
1826; earlier (1825).the American Mechanies Magazine. 

1832—. Annalen der Chemie (und Pharmacie) often known 
as Liebig’s Annalen. Leipzig, Lemgo. 


THe FOUNDER OF THE AMERICAN JOURNAL OF SCIENCE. 


The establishment of a scientific journal in this country 
in 1818 was a pioneer undertaking, requiring of its 
founder a rare degree of energy, courage, and confidence 
in the future. It was necessary, not only to obtain the 
material to fill its pages and the money to carry on the 
enterprise, but, before the latter end could be accom- 
plished, an audience must be found among those who had 
hitherto felt little or no interest in the sciences. This 
ereat work was accomplished by Benjamin Silliman, 
‘the guardian of American Science,’’ whose influence 
was second to none in the early development of science in 
this country. Before speaking in some detail of the 
early years of this Journal and of its subsequent history, 
it is proper that some words should be given to its 
founder. 

Benjamin Silliman, son of a general prominent in the 
Revolutionary War, was born in Trumbull, Connecticut, 
on August 8, 1779. He was a graduate of Yale College 
of the class of 1796. Though at first a student of law and 
accepted for the bar in Connecticut, he was called in 1802 
by President Timothy Dwight—a man of rare breadth of 
mind—to occupy the newly-made chair of chemistry, min- 
eralogy (and later geology) in Yale College at New 
Haven. To fit himself for the work before him he 
earried on extensive studies at home and in Philadelphia 
and spent the year 1805 in travels and study at London 
and Edinburgh, and also on the Continent. His active 
duties began in 1806 and from this time on he was in the 
service of Yale College until his resignation in 1853. 
From the first, Silliman met with remarkable success as a 
teacher and public lecturer in arousing an interest in 
science. His breadth of knowledge, his enthusiasm for 
his chosen subjects and power of clear presentation, com- 
bined with his fine presence and attractive personality, 
made him a great leader in the science of the country and 
gave him a unique position in the history of its develop- 
ment. 

Much might be said of the man and his work, but, the 


\ 


12 Dana—American Journal of Science, 1818-1918. 


best tribute is that of James Dwight Dana, given in his 
inaugural address upon the occasion of his beginning his 
duties as Silliman professor of geology in Yale College. 
This was delivered on February 18, 1856, in what was 
then known as the ‘‘Cabinet Building.’’ Dana says 
In part: 


‘In entering upon the duties of this place, my thoughts turn — 
rather to the past than to the subject of the present hour. I 
feel that it is an honored place, honored by the labors of one 
who has been the guardian of American Science from its child- 
hood; who here. first opened to the country the wonderful. 
records of geology; whose words of eloquence and earnest truth 
were but the overflow of a soul full of noble sentiments and 
warm sympathies, the whole throwing a peculiar charm over 
his learning, and rendering his name beloved as well as illus- 
trious. Just fifty years since, Professor Silliman took his sta- 
tion at the head of chemical and geological science in this college. 
Geology was then hardly known by name in the land, out of 
these walls. Two years before, previous to his tour in Europe, 
the whole cabinet of Yale was a half-bushel of unlabelled stones. 
On visiting England he found even in London no school public 
or private, for geological instruction, and the science was not 
named in the English universities. To the mines, quarries, and 
cliffs of England, the crags of Scotland, and the meadows of 
Holland he looked for knowledge, and from these and the teach- 
ines of Murray, Jameson, Hall, Hope, and Playfair, at Edin- 
burgh, Professor Silliman returned, equipped for duty,—albeit 
a great duty,—that of laying the foundation, and creating 
almost out of nothing a department not before recognized in any 
institution in America. 

He began his work in 1806. The science was without books— 
and, too, without system, except such as its few cultivators had 
each for himself in his conceptions. It was the age of the first 
beginnings of geology, when Wernerians and Huttonians were 
arrayed in a contest. . . . Professor Silliman when at Edin- 
burgh witnessed the strife, and while, as he says, his earliest 
predilections were for the more peaceful mode of rock-making, 
these soon yielded to the accumulating evidence, and both views 
became combined in his mind in one harmonious whole. The 
science, thus evolved, grew with him and by him; for his own 
labors contributed to its extension. Every year was a year of 
expansion and onward development, and the grandeur of the 
opening views found in him a ready and appreciative response. 


And while the sciences and truth have thus made progress 
here, through these labors of fifty years, the means of study in 
the institution have no less increased. Instead of that half- 


Dana—American Journal of Science, 1818-1918. 13 


bushel of stones, which once went to Philadelphia for names, in 
a candle-box, you see above the largest mineral cabinet in the 
country, which but for Professor Silliman, his attractions and 
his personal exertions together, would never have been one of 
the glories of old Yale. 

Moreover, the American J ournal of Science,—now in its 
thirty-seventh year and seventieth volume [1856] ,— projected 
and long-sustained solely by Professor Silliman, while ever dis- 
tributing truth, has also been ever gathering honors, and is one 
of the laurels of Yale. 

We rejoice that in laying aside his studies, after so many 
years of labor, there is still no abated vigor. . . . He retires 
as one whose right it is to throw the burden on others. Long 
may he be with us, to enjoy the good he has done, and cheer us 
by his noble and benign presence.’’ 


In addition to these words of Dana, much of vital 
interest in regard to Silliman and his work will be 
gathered from what is given in the pages immediately 
following, quoted from his personal statements in the 
early volumes of the Journal. 


THe Earuty YEARS OF THE JOURNAL. 


In no direction did Silliman’s enthusiastic activities in 
science produce a more enduring result than in the found- 
ing and carrying on of this Journal. The first sugges- 
tion in regard to the enterprise was made to Silliman by 
his friend, Colonel George Gibbs, from whom the famous 
Gibbs collection of minerals was bought by Yale College 
in 1825. Silliman says (25, 215, 1834): 


‘“Col. Gibbs was the person who first suggested to the Editor 
the project of this Journal, and he urged the topic with so much 
zeal and with such cogent arguments, as prevailed to induce the 
effort in a case then viewed as of very dubious success. The 
subject was thus started in November, 1817; proposals for the 
Journal were issued in January, 1818, and the first number 
appeared in July of that year.’’ 


He adds further (50, p. iii, 1847) that the conversation 
here recorded took place “on an accidental meeting on 
board the steamboat Fulton in Long Island Sound.’’ 
This was some ten years after Robert Fulton’s steam- 
boat, the Clermont, made its pioneer trip on the Hudson 
river, already alluded to. The incident is not without 
significance in this connection. The deck of the ‘‘Ful- 


AMERICAN 


JOURNAL OF SCUBNCIE, 


WAG; : MORE POREGIAEEY OF 
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CONDUCTED BY 
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PROFESSOR OF CHEMISTRY. MINERALOGY. ETC IN YALE COLLEGE, AUTHOR OF 
TRAVELS IN ENGLAND. SCOTLAND. AND HOLLAND, ETC 


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VOL. I.....NO. I. 
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ENGRAVING IN THE PRESENT NO. 


New apparatus for the combustion of Tar, &c. by the vapour of 
water. 


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Pew-ork : 


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ria PUBLISHED BY J. FASTBURN AND CO. LITERARY ROOMS, BROADWAY, 
AND BY HOWE AND SPALDING, NEW-HAVEN. 
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Abraham Paul, printer. 


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Dana—American Journal of Science, 1818-1918. 15 


ton’’ was not an inappropriate place for the inauguration 
of an enterprise also great in its results for the country. 

In the preface to the concluding volume of the First 
Series (loc. cit.) Silliman adds the following remarks 
which show his natural modesty at the thought of under- 
taking so serious a work. He says: 


Although a different selection of an editor would have been 
much preferred, and many reasons, public and personal, con- 
curred to produce diffidence of success, the arguments of Col. 
Gibbs, whose views on subjects of science were entitled to the 
most respectful consideration, and had justly great weight, 
being pressed with zeal and ability, induced a reluctant assent; 
and accordingly, after due consultation with many competent 
judges, the proposals were issued early in 1818, embracing the 
whole range of physical science and its applications. The 
Editor in entering on the duty, regarded it as an affair for life, 
and the thirty years of experience which he has now had, have 
proved that his views of the exigencies of the service were not 
erroneous. 


The plan with which the editor began his work and the 
lines laid down by him at the outset can only be made 
clear by quoting entire the ‘‘Plan of the Work’’ which 
opens the first number. It seems desirable also to give 
this in its original form as to paragraphs and typog- 
raphy. The first page of the cover of the opening num- 
ber has also been reproduced here. It will be seen that 
the plan of the young editor was as wide as the entire 
range of science and its applications and extended out to 
music and the fine arts. This seems strange to-day, but 
it must be remembered how few were the organs of pub- 
lication open to contributors at the time. If the plan 
was unreasonably extended, that fact is to be taken not 
only as an expression of the enthusiasm of the editor, as 
yet inexperienced in his work, but also of the time when 
the sciences were still in their infancy. 

He says (1, pp. v, vi): 


“PLAN OF THE WORK. 


This Journal is intended to embrace the circle of THE PHys- 
ICAL SCIENCES, with their application to THE Arts, and to every 
useful purpose. 

It is designed as a deposit for original American communica- 
tions; but will contain also occasional selections from Foreign 
J ournals, and notices of the progress of science in other coun- 
tries. Within its plan are embraced 


16 Dana—American Journal of Science, 1818-1918. 


Natura History, in its three great departments of MInER- 
ALOGY, Borany, and Zoouoey ; 

CHEMISTRY and NatTuRAL PHILOSOPHY, in their various 
branches: and MATHEMATICS, pure and mixed. 

It will be a leading object to illustrate American NaturaAu 
History, and especially our Mineratocy and GHonoey. 

The AppLicaTIONS of these sciences are obviously as numer- 
ous as physical arts, and physical wants; for no one of these 
arts or wants can be named which is not connected with them. 

While ScreNceE will be cherished for tts own sake, and with a 
due respect for its own wmherent dignity; it will also be 
employed as the handmad to the Arts. Its numerous applica- 
tions to AGRICULTURE, the earliest and most important of them; 
to our MANUFACTURES, both mechanical and chemical; and 
to our Domestic Economy, will be carefully sought out, and 
faithfully made. 

It is also within the design of this Journal to receive communi- 
cations on Music, ScuLPTURE, ENGRAVING, PAINTING, and gener- 
ally on the fine and liberal, as well as useful arts; 

On Military and Civil Engineering, and the art of Navigation. 

Notices, Reviews, and Analyses of new scientific works, and 
of new Inventions, and Specifications of Patents; 

Biographical and Obituary Notices of scientific men; essays 
on CoMPARATIVE ANATOMY and PHystioLoGcy, and generally on 
such other branches of medicine as depend on scientific prin- 
ciples ; 

Meteorological Registers, and Reports of Agricultural Experi- 
ments: and we would leave room also for interesting miscellane- 
ous things, not perhaps exactly included under either of the 
above heads. 

Communications are respectfully solicited from men of 
science, and from men versed in the practical arts. 

Learned Societies are invited to make this Journal, occasion- 
ally, the vehicle of their communications to the Public. 

The editor will not hold himself responsible for the sentiments 
and opinions advanced by his correspondents; but he will con- 
sider it as an allowed liberty to make slight verbal alterations, 
where errors may be presumed to have arisen from inadver- 
tency.’ 


In the ‘‘Advertisement’’ which precedes the above 
statement in the first number, the editor remarks some- 
what naively that he ‘‘does not pledge himself that all the 
subjects shall be touched upon in every number. This is 
plainly impossible unless every article should be very 
short and imperfect. . .’’ ) 

The whole subject is discussed in all its relations in 
the ‘‘Introductory Remarks’’ which open the first vol- 


Dana—American Journal of Science, 1818-1918. 17 


ume. No apology is needed for quoting at considerable 
length, for only in this way can the situation be made 
clear, as seen by the editor in 1818. Further we gain 
here a picture of the intellectual life of the times and, not 
less interesting, of the mind and personality of the writer. 
With a frank kindliness, eminently characteristic of the 
man, as will be seen, he takes the public fully into his 
confidence. In the remarks made in subsequent vol- 
umes,—also extensively quoted—the vicissitudes in the 
conduct of the enterprise are brought out and when suc- 
cess was no longer doubtful, there is a tone of quiet 
satisfaction which was also characteristic and which the 
circumstances fully justified. 
The Inrropuctory Remarks begin as follows: 


The age in which we live is not less distinguished by a vigorous 
and successful cultivation of physical science, than by its numer- 
ous and important applications to the practical arts, and to the 
common purposes of life. 

In every enlightened country, men illustrious for talent, worth 
and knowledge, are ardently engaged in enlarging the bound- 
aries of natural science; and the history of their labors and 
discoveries 1s communicated to the world chiefly through the 
medium of scientific journals. The utility of such journals has 
thus become generally evident; they are the heralds of science; 
they proclaim its toils and its achievements; they demonstrate 
its intimate connection as well with the comfort, as with the 
intellectual and moral improvement of our species; and they 
often procure for it enviable honors and substantial rewards. 


Mention is then made of the journals existing in 
England and France in 1818 ‘‘which have long enjoyed a 
high and deserved reputation.’’ He then continues: 


From these sources our country reaps and will lone continue 
to reap, an abundant harvest of information: and if the light 
of science, as well as of day, springs from the East, we will wel- 
come the rays of both; nor should national pride induce us to 
reject so rich an offering. 

But can we do nothing in return? 

In a general diffusion of useful information through the vari- 
ous classes of society, in activity of intellect and fertility of 
resource and invention, producing a highly intelligent popula- 
tion, we have no reason to shrink from a comparison with any 
country. But the devoted cultivators of science in the United 
States are comparatively few: they are, however, rapidly 
increasing in number. Among them are persons distinguished 
for their capacity and attainments, and, notwithstanding the 


18 Dana—American Journal of Science, 1818-1918. 


local feelings nourished by our state sovereignties, and the rival 
claims of several of our larger cities, there is evidently a predis- 
position towards a concentration of effort, from which we may 
hope for the happiest results, with regard to the advancement 
of both the science and reputation of our country. 

Is it not, therefore, desirable to furnish some rallying point, 
some object sufficiently interesting to be nurtured by common 
efforts, and thus to become the basis of an enduring, common 
interest? To produce these efforts, and to excite this interest, 
nothing, perhaps, bids fairer than a ScIENTIFIC JOURNAL. 


The valuable work already accomplished by various 
medical journals is then spoken of and particularly that 
of the first scientific periodical in the United States, 
Bruce’s Mineralogical Journal. This, as Silliman says 
(1, p. 3, 1818), although ‘‘both in this country and in 
Europe received in a very flattering manner,’’ did not 
survive the death of its founder, and only a single vol- 
ume of 270 pages appeared (1810-1813). 
Silliman continues : 


No one, it is presumed, will doubt that a journal devoted to 
science, and embracing a sphere sufficiently extensive to allure 
to its support the principal scientific men of our country, is 
ereatly needed; if cordially supported, it will be successful, 
and if successful, it will be a great public benefit. 

Even a failure, in so good a cause, (unless it should arise from 
incapacity or unfaithfulness,) cannot be regarded as dishonour- 
able. It may prove only that the attempt was premature, and 
that our country is not yet ripe for such an undertaking; for 
without the efficient support of talent, knowledge, and money, 
it cannot long proceed. No editor can hope to carry forward 
such a work without the active aid of scientific and practical 
men; but, at the same time, the public have a right to expect 
that he will not be sparing of his own labour, and that his work 
shall be generally marked by the impress of his own hand. To 
this extent the editor cheerfully acknowledges his obligations 
to the public; and it will be his endeavour faithfully to redeem 
his pledge. 

Most of the periodical works of our country have been short- 
lived. This, also, may perish in its infancy; and if any degree 
of confidence is cherished that it will attain a maturer age, it is 
derived from the obvious and intrinsic importance of the under- 
taking; from its being built upon permanent and momentous 
national interests; from the evidence of a decided approbation 
of the design, on "the part of gentlemen of the first eminence, 
obtained in the progress of an extensive correspondence; from 
assurance of support, in the way of contributions, from men of 


Dana—American Journal of Science, 1818-1918. 19 


ability in many sections of the union; and from the existence 
of such a crisis in the affairs of this country and of the world, 
as appears peculiarly auspicious to the success of every wise and 
good undertaking. 


An interesting discussion follows (pp. 5-8) as to the 
claims of the different branches of science, and the extent 
to which they and their applications had been already 
developed, also the spheres still open to discovery. 

The Introductory Remarks close, as follows: 


In a word, the whole circle of physical science is directly 
applicable to human wants and constantly holds out a light to 
the practical arts; it thus polishes and benefits society and 
everywhere demonstrates both supreme intelligence and harmony 
and beneficence of design in the Creator. 

The science of mathematics, both pure and mixed, can never 
cease to be interesting and important to man, as long as the 
relations of quantity shall exist, as long as ships shall traverse 
the ocean, as long as man shall measure the surface or heights 
of the earth on which he lives, or ecaleulate the distances and 
examine the relations of the planets and stars; and as long as 
the tron reign of war shall demand the discharge of projectiles, 
or the construction of complicated defences. 


The closing part of the paragraph shows the influence 
exerted upon the mind of the editor by the serious wars 
of the years preceding 1818, a subject alluded to again at 
the close of this chapter. 


In February, 1822, with the completion of the fourth 
volume, the editor reviews the situation which, though 
encouraging is by no means fully assuring. He says 
(preface to vol. 4, dated Feb. 15, 1822): 


Two years and a half have elapsed, since the publication of 
the first volume of this Journal, and one year and ten months 
since the Editor assumed the. pecuniary responsibility. } 

The work has not, even yet, reimbursed its expenses, (we 
speak not of editorial or of business compensation,) we intend, 
that it has not paid for the paper, printing and engraving; the 
proprietors of the first volume being in advance, on those 
accounts, and the Editor on the same score, with respect to the 
ageregate expense of the three last volumes. This deficit is, 
however, no longer increasing, as the receipts, at present, just 
about cover the expense of the physical materials, and of the 
manual labour. A reiterated disclosure of this kind is not 
erateful, and would scarcely be manly, were it not that the 
public, who alone have the power to remove the difficulty, have 


20 Dana—American Journal of Science, 1818-1918. 


a right to a frank exposition of the state of the case. As the 
patronage is, however, growing gradually more extensive, it is 
believed that the work will be eventually sustained, although 
it may be long before it will command any thing but gratuitous 
intellectual labour. : 

These facts, with the obvious one,—that its pages are supplied 
with contributions from all parts of the Union, and occasionally 
from Europe, evince that the work is received as a national and 
not as a local undertaking, and that the community consider it 
as having no sectional character. Encouraged by this view of 
the subject, and by the favour of many distinguished men, both 
at home and abroad, and supported by able contributors, to 
whom the Editor again tenders his grateful acknowledgments, 
he will still persevere, in the hope of contributing something 
to the advancement of our science and arts, and towards the 
elevation of our national character. 


In the autumn of the same year, the editor closes the 
fifth volume with a more confident tone (Sept. 25, 1822) : 


A trial of four years has decided the point, that the American 
Public will support this Journal. Its pecuniary patronage is 
now such, that although not a lucrative, it is no longer a hazard- 
ous enterprise. It is now also decided, that the intellectual 
resources of the country are sufficient to afford an unfailing 
supply of valuable original communications and that nothing 
but perseverance and effort are necessary to give perpetuity to 
the undertaking. 

The decided and uniform expression of public favour which 
the Journal has received both at home and abroad, affords the 
Editor such encouragement, that he cannot hesitate to per- 
severe—and he now renews the expression of his thanks to the 
friends and correspondents of the work, both in Europe and the 
United States, requesting at the same time a continuance of their 
friendly influence and efforts. 


Still again in the preface to the sixth volume (1823) he 
takes the reader more fully into his confidence and shows 
that he regards the enterprise as no longer of doubtful 
success. He says: 


The conclusion of a new volume of a work, involving so much 
eare, labour and responsibility, as are necessarily attached, at 
the present day, to a Journal of Science and the Arts, natur- 
ally produces in the mind, a state of not ungrateful calmness, 
and a disposition, partaking of social feeling, to say something 
to those who honour such a production, by giving to it a small 
share of their money, and of their time. The Editor’s first 
impression was, that the sixth volume should be sent into the 


(2204 


Dana—American Journal of Science, 1818-1918. 21 


world without an introductory note, but he yields to the impulse 
already expressed, and to the established usages of respectful, 


courtesy to the public, which a short preface seems to imply. 


He has now persevered almost five years, in an undertaking, 
regarded by many of the friends whom he originally consulted, 
as hazardous, and to which not a few of them prophetically 
alloted only an ephemeral existence. It has been his fortune to 
prosecute this work without, (till a very recent period,) returns, 
adequate to its indispensable responsibilities ;—under a heavy 
pressure of professional and private duty; with trying fluctua- 
tions of health, and amidst sévere and reiterated domestic 
afflictions. The world are usually indulgent to allusions of this 
nature, when they have any relation to the discharge of public 
duty; and in this view, it is with satisfaction, that the Editor 
adds, that he has now to look on formidable difficulties, only in 
retrospect, and with something of the feeling of him, who sees 
a powerful and vanquished foe, slowly retiring, and leaving a 
field no longer contested. 

This Journal which, from the first, was fully supplied with 
original communications, is now sustained by actual payment, 
to such an extent, that it may fairly be considered as an estab- 
lished work; its patronage is regularly increasing, and we trust 
it will no longer justify such remarks as some of the following, 
from the pen of one of the most eminent scientific men in 
Europe. ‘‘Nothing surprises me more, than the little encourage- 
ment which your Journal,’’ (‘‘which I always read with very 
great interest, and of which I make great use,’’) ‘‘experiences 
in America—this must surely arise from the present depressed 
condition of trade, and cannot long continue.’’ 


Six years more of uninterrupted editorial work passed 
by, the sixteenth volume was completed, and the editor 
was now in a position to review the whole situation up to 
1829. This preface (dated July 1, 1829), which is quoted 
nearly in full, cannot fail to be found particularly inter- 
esting and from several standpoints, not the least for the 
insight it gives into the writer’s mind. It is also note- 
worthy that at this early date it was found possible to 
pay for original contributions, a privilege far beyond 
the means of the editor of to-day. 


When -this Journal was first projected, very few believed that 
it would succeed. 

Among others, Dr. Dorsey wrote to the editor; ‘‘I predict a 
short life for you, although I wish, as the Spaniards say, that 
you may live a thousand years.’’ The work has not lived a 
thousand years, but as it has survived more than the hundredth 
part of that period, no reason is apparent why it may not con- 


22 Dana—American Journal of Science, 1818-1918. 


tinue to exist. To the contributors, disinterested and arduous 
*.as have been their exertions, the editor’s warmest thanks are 
~ due; and they are equally rendered to numerous personal 
friends for their unwavering support: nor ought those sub- 
seribers to be forgotten who, occupied in the common pursuits 
of life, have aided, by their money, in sustaining the hazardous 
novelty of an American Journal of Science. A general appro- 
bation, sufficiently decided to encourage effort, where there was 
no other reward, has supported the editor; but he has not been 
inattentive to the voice of eriticism, whether it has reached him 
in the tones of candor and kindness, or in those of severity. 
We must not look to our friends for the full picture of our 
faults. He is unwise who neglects the maxim— 


—fas est ab hoste doceri, 


and we may be sure, that those are quite in earnest, whose 
pleasure it is, to place faults in a strong hght and bold relief; 
and to throw excellencies into the shadow of total eclipse. 
Minds at once enlightened and amiable, viewing both in their 
proper proportions, will however render the equitable verdict; 


Non ego paucis offendar maculis,— 


It is not pretended that this Journal has been faultless; there 
may be communications in it which had been better omitted, and 
it is not doubted that the power to command intellectual effort, 
by suitable pecuniary reward, would add to its purity, as a 
record of science, and to its richness, as a repository of dis- 
coveries in the arts. 

But the editor, even now, offers payment, at the rate adopted 
by the literary Journals, for able original communications, con- 
taining especially important facts, investigations and discoveries 
in science, and practical inventions in the useful and ornamental 
Arts. 

As however his means are insufficient to pay for all the copy, 
it is earnestly requested, that those gentlemen, who, from other 
motives, are still willing to write for this Journal, should con- 
tinue to favor it with their communications. That the period 
when satisfactory compensation can be made to all writers whose 
pieces are inserted, and to whom payment will be acceptable, is 
not distant, may perhaps be hoped, from the spontaneous expres- 
sion of the following opinion, by the distinguished editor of one 
of our principal literary journals, whose letter is now before 
me. ‘‘The character of the American Journal is strictly 
national, and it is the only vehicle of communication in which ‘— 
an inquirer may be sure to find what is most interesting in the 
wide range of topics, which its design embraces. It has become 
in short, not more identified with the science than the literature 
of the country.’’ It is believed that a strict examination of 
its contents will prove that its character has been decidedly 


Dana—American Journal of Science, 1818-1918. 23 


scientific; and the opinion is often expressed to the editor, that 
in common with the journals of our Academies, it is a work of 
reference, indispensable to him who would examine the progress 
of American science during the period which it covers. That it 
might not be too repulsive to the general reader, some miscel- 
laneous pieces have occasionally occupied its pages; but in 
smaller proportion, than is common with several of the most 
distinguished British Journals of Science. 

Still, the editor has been frequently solicited, both in public 
and private, to make it more miscellaneous, that it might be 
more acceptable to the intelligent and well educated man, who 
does not cultivate science; but he has never lost sight of his 
great object, which was to produce and concentrate original 
American effort in science, and thus he has foregone pecuniary 
returns, which by pursuing the other -course, might have been 
rendered important. Others would not have him admit any 
thing that is not strictly and technically scientific; and would 
make this journal for mere professors and amateurs; especially 
in regard to those numerous details in natural history, which 
although important to be registered, (and which, when pre- 
sented, have always been recorded in the American Journal, ) 
can never exclusively occupy the pages of any such work without 
repelling the majority of readers. 


If this is true even in Great Britain it is still more so in this. 


country; and our savants, unless they would be, not only the 
exclusive admirers, but the sole purchasers of their own works, 
must permit a little of the graceful drapery of general literature 
to flow around the cold statues of science. The editor of this 
Journal, strongly inclined, both from opinion and habit, to 
gratify the cultivators of science, will still do everything in his 
power to promote its high interests, and as he hopes in a better 
manner than heretofore; but these respectable gentlemen will 
have the courtesy, to yield something to the reading literary, as 
well as scientific public, and will not, we trust, be disgusted, 
if now and then an Oasis relieves the eye, and a living stream 
refreshes the traveller. Not being inclined to renew the abortive 
experiment, to please every body, which has been so long 
renowned in fable; the editor will endeavor to pursue, the 
even tenor of his way; altogther inclined to be courteous and 
useful to his fellow travellers, and hoping for their kindness 
and services in return. 


THE CLOSE OF THE First Series. 


The ‘‘First Series,’’ as it was henceforth to be known, 
closed with the fiftieth volume (1847, pp. xx + 347). 
This final volume is devoted to an exhaustive index to the 
forty-nine volumes preceding. In the preface (dated 
April 19, 1847) the elder Silliman, now the senior editor, 


24 Dana—American Journal of Science, 1818-1918. 


reviews the work that had been accomplished with a 
frank expression of his feeling of satisfaction in the vic- 
tory won against great obstacles; with this every reader 
must sympathize. He quotes here at length (but in 
slightly altered form) the matter from the first volume 
(1818), which has been already reproduced almost 
entire, and then goes on as follows (pp. xi et seq.) : 


Such was the pledge which, on entering upon our editorial 
labors in 1818, we gave to the public, and such were the views 
which we then entertained, regarding science and the arts as 
connected with the interests and honor of our country and of 
mankind. In the retrospect, we realize a sober but grateful 
feeling of satisfaction, in having, to the extent of our power, 
discharged these self-imposed obligations; this feeling is chas- 
tened also by a deep sense of gratitude, first to God for life and 
power continued for so high a purpose; and next, to our noble 
band of contributors, whose labors are recorded in half a century 
of volumes, and in more than a quarter of a century of years. 
We need not conceal our conviction, that the views expressed 
in these ‘‘Introductory Remarks,’’ have been fully sustained 
by our fellow laborers. 

Should we appear to take higher ground than becomes us, 
we find our vindication in the fact, that we have heralded 
chiefly the doings and the fame of others. The work has indeed 
borne throughout ‘‘the impress’’ of editorial unity of design, 
and much that has flowed from one pen, and not a little from 
the pens of others, has been without a name. The materials 
for the pile, have however been selected and brought in, chiefly 
by other hands, and if the monument which has been reared 
should prove to be ‘‘aere perennius,’’ the honor is not the sole 
property of the architect; those who have quarried, hewn and 
polished the granite and the marble, are fully entitled to the 
enduring record of their names already deeply cut into the 
massy blocks, which themselves have furnished. 

Diva retrospective survey of the labors of thirty years on this 
occasion has rekindled a degree of enthusiasm, it is a natural 
result of an examination of all our volumes from the contents 
of which we have endeavored to make out a summary both of 
the laborers and their works. ; 

The series of volumes must ever form a work of permanent 
interest on account of its exhibiting the progress of American 
science. during the long period which it covers. Comparing 
1817 with 1847, we mark on this subject a very gratifying change. 
The cultivators of science in the United States were then few— 
now they are numerous. Societies and associations of various 
names, for the cultivation of natural history, have been insti- 
tuted in very many of our cities and towns, and several of them 


Dana—American Journal of Science, 1818-1918. 25 


have been active and efficient in making original observations 
and forming collections. 


A summary follows presenting some facts as to the 
erowth of scientific societies and scientific collections in 
this country during the period involved: Then the 
striking contrast between 1818 and 1847 in the matter of 
organized effort toward scientific exploration is dis- 
cussed, as follows (pp. xvi et seq.): 


When we began our Journal, not one of the States had been 
surveyed in relation to its geology and natural history; now 
those that have not been explored are few in number. State 
collections and a United States Museum hold forth many allure- 
ments to the young naturalist, as well as to the archzxologist and 
the student of his own race. The late Exploring Expedition 
[Wilkes] with the National Institute, has enriched the capital 
with treasures rarely equalled in any country, and the Smith- 
sonian Institution recently organized at Washington, is about 
to begin its labors for the increase and diffusion of knowledge 
among men. 

It must not be forgotten that the American Association of 
Geologists and Naturalists—composed of individuals assembled 
from widely separate portions of the Union—by the seven ses- 
sions which it has held, and by its rich volume of reports, has 
produced a concentration and harmony of effort which promise 
happy results, especially as, like the British Association, it 
visits different towns and cities in its annual progress. 

Astronomy now lifts its exploring tubes from the observatories 
of many of our institutions. Even the Ohio, which within the 
memory of the oldest living men, rolled along its dark waters 
through interminable forests, or received the stains of blood 
from deadly Indian warfare, now beholds on one of its most 
beautiful hills, and near its splendid city, a permanent obser- 
vatory with a noble telescope sweeping the heavens, by the hand 
of a zealous and gifted observer. At Washington also, under 
the powerful patronage of the general government, an excellent 
observatory has been established, and is furnished with superior 
instruments, under the direction of a vigilant and well instructed 
astronomer—seconded by able and zealous assistants. 

Here also (in Yale College) successful observations have been 
made with good instruments, although no permanent building 
has been erected for an Observatory. 

We cnly give single examples by way of illustration, for the 
history of the progress of science in the United States, and of 
institutions for its promotion, during the present generation, 
would demand a volume. It is enough for our purpose that 
science is understood and valued, and the right methods of 
prosecuting it are known, and the time is at hand when its moral 


6 
26 Dana—American Journal of Science, 1818-1918. 


and intellectual use will be as obvious as its physical applica- 
tions. Nor is it to be forgotten that we have awakened an 
European interest in our researches: general science has been 
illustrated by treasures of facts drawn from this country, and 
our discoveries are eagerly sought for and published abroad. 

While with our co-workers in many parts of our broad land, 
we rejoice in this auspicious change, we are far from arrogating 
it to ourselves. Multiplied labors of many hands have produced 
the great results. In the place which we have occupied, we 
have persevered despite of all discouragements, and may, with 
our numerous coadjutors, claim some share in the honors of the 
day. We do not say that our work might not have been better 
done—but we may declare with truth that we have done all in 
our power, and it is something to have excited many others to 
effort and to have chronicled their deeds in our annals. Let 
those that follow us labor with like zeal and perseverance, and 
the good cause will continue to advance and prosper. It is the 
cause of truth—science is only embodied and sympathized truth 
and in the beautiful conception of our noble Agassiz—‘‘it tells 
the thought of God.”’ 


The preface closes with some personal remarks: 


In tracing back the associations of many gone-by years, a 
host of thoughts rush in, and pensive remembrance, of the dead 
who have labored with us casts deep shadows into the vista 
through which we view the past. 

Anticipation of the hour of discharge, when our summons 
shall arrive, gives sobriety to thought and checks the confidence 
which health and continued power to act might naturally inspire, 
were we not reproved, almost every day, by the death of some 
co-eval, co-worker, companion, friend or patron. This very hour 
is saddened by such an event,—but we will continue to labor 
on, and strive to be found at our post of duty, until there is 
nothing more for us to do; trusting our hopes for a future life 
in the hands of Him who placed us in the midst of the splendid 
garniture of this lower world, and who has made not less ample 
provision for another and a better. 


Editorial and financial.—The editorial labors on the 
Journal were carried by the elder Silliman alone for 
twenty years from 1818 to 1838. As has been clearly 
shown in his statements, already quoted, he was, after the 
first beginning, personally responsible also for the finan- 
cial side of the enterprise. With volume 34 (1838) the 
name of Benjamin Silliman, Jr., is added as co-editor on 
the title page. He was graduated from Yale College the 
year preceding and at this date was only twenty-one 
years old. His aid was unquestionably of much service 


7 


Dana—American Journal of Science, 1818-1918. 27 


from the beginning and increased rapidly with years and 
experience. The elder Silliman introduces him in the 
preface to vol. 34 (1838) and comes back to the subject 
again in the preface to vol. 50 (1847). The whole edi- 
torial situation is here presented as follows: 


‘*During twenty years from the inception of this Journal, the 
editor labored alone, although overtures for editorial co-opera- 
tion had been made to him by gentlemen commanding his con- 
fidence and esteem, and who would personally have been very 
acceptable. It was, however, his opinion that the unity of 
purpose and action so essential to the success of such a work 
were best secured by individuality; but he made every effort, 
and not without success, to conciliate the good will and to secure 
the assistance of gentlemen eminent in particular departments 
of knowledge. On the title page of No. 1, vol. 34, published in 
July. 1838, a new name is introduced: the individual to whom 
it belongs having been for several years more or less concerned 
in the management of the Journal, and from his education, 
position, pursuits and taste, as well as from affinity, being almost 
identified with the editor, he seemed to be quite a natural ally, 
and his adoption into the editorship was scarcely a violation of 
individual unity. His assistance has proved to be very import- 
ant:—his near relation to the senior editor prevents him from 
saying more, while justice does not permit him to say less.’’ 


As is distinctly intimated in the preceding paragraph 
the elder Silliman was fortunate in obtaining the assist- 
ance in his editorial labors of numerous gentlemen inter- 
ested in the enterprise. Their codperation provided 
many of the scientific notices, book reviews and the like 
contained in the Miscellany with which each number 
closed. It is impossible, at this date, to render the credit 
due to Silliman’s helpers or even to mention them by 
name. Very early Asa Gray was one of these as occa- 
sional notes are signed by his initials. Dr. Levi Ives of 
New Haven was another. Prof. J. Griscom of Paris also 
sent numerous contributions even as early as 1825 (see 
a, fo4, 1825; 22, 192,.1832; 24, 342, 1833, and others). 

Some statements have already been quoted from the 
early volumes as to the business part of Silliman’s enter- 
prise. The subject is taken up more fully in the preface 
to volume 50 (1847). No one can fail to marvel at the 
energy and optimism required to push the Journal for- 
ward when conditions must have been so difficult and 
encouragement so scanty. He says (pp. 1), Iv): 


28 Dana—American Journal of Science, 1818-1918. 


This Journal first appeared in July, 1818, and in June, 1819, 
the first volume of four numbers and 448 pages was completed. 
This scale of publication, originally deemed sufficient, was found 
inadequate to receive all the communications, and as the receipts 
proved insufficient to sustain the expenses, the work, having but 
three hundred and fifty subscribers, was, at the end of the year, 
abandoned by the publishers. 

An unprofitable enterprise not being attractive to the trade, 
ten months elapsed before another arrangement could be carried 
into effect, and, therefore, No. 1 of vol. 2 was not published until 
April, 1820. The new arrangement was one of mutual responsi- 
bility for the expenses, but the Editor was constrained neverthe- 
less to pledge his own personal credit to obtain from a bank the 
funds necessary to begin again, and from this responsibility he 
was, for a series of years, seldom released. The single volume 
per annum being found insufficient for the communications, 
two volumes a year were afterward published, commencing with 
the second volume. 


The publishers whose names appear on the title page 
of the four numbers of the first volume are ‘‘J. Kastburn 
& Co., Literary Rooms, Broadway, New York’’ and Howe 
& Spalding, New Haven.’’ For the second volume and 
those immediately following the corresponding state- 
ment ‘‘printed and published by 8S. Converse [New 
Haven] for the Editor.’’ 


Silliman adds (p. iv): 


At the conclusion of vol. 10, in February, 1826, the work was 
again left upon the hands of its Editor; all its receipts had been 
absorbed by the expenses, and it became necessary now to pay 
a heavy sum to the retiring publisher, as an equivalent for his 
copies of previous volumes, as it was deemed necessary either 
to control the work entirely or to abandon it. The Editor was 
not willing to think of the latter, especially as he was encouraged 
by public approbation, and was cheered onward in his labors by 
eminent men both at home and abroad, and he saw distinctly 
that the Journal was rendering service not only to science and 
the arts, but to the reputation of his country. He reflected, 
moreover, that in almost every valuable enterprise perseverance 
in effort is necessary to success. He being now sole proprietor, 
a new arrangement was made for a single year, the publishers 
being at liberty, at the end of that time, to retire, and the Editor 
to resume the Journal should he prefer that course. 

The latter alternative he adopted, taking upon himself the 
entire concern, including both the business and the editorial 
duties, and of course, all the correspondence and accounts. 
From that time the work has proceeded without interruption, 
two volumes per annum having been published for the last 


Dana—American Journal of Science, 1818-1918. 29 


twenty years; and its pecuniary claims ceased to be onerous, 
although its means have never been large. 


Later in the same preface he adds (p. xiv): 


It may be interesting to our readers to know something of the 
patronage of the Journal. It has never reached one thousand 
paying subscribers, and has rarely exceeded seven or eight 
hundred—for many years it fluctuated between six and seven 
hundred. 

It has been far from paying a reasonable editorial compensa- 
tion; often it has paid nothing, and at present it does little 
more than pay its bills. The number of engravings and the 
extra labor in printer’s composition, cause it to be an expensive 
work, while its patronage is limited. 


It is difficult at this date to give any adequate state- 
ment of the amount of encouragement and active assist- 
ance given to Silliman by his scientific colleagues in New 
Haven and elsewhere—a subject earlier alluded to. It 
is fortunately possible, however, to acknowledge the gen- 
erous aid received by the Journal in the early days from 
a source near at hand. It has already been noted in 
another place that the dawning activity of science at New 
Haven was recognized by the founding of the ‘‘ Connecti- 
eut Academy of Arts and Sciences,’’ formally estab- 
lished at New Haven in 1799 and the third scientific body 
to be organized in this country. From the beginning of 
the Journal in 1818, the Connecticut Academy freely 
gave its support both in papers for publication and at 
least on one occasion later it gave important financial aid. 
Upon the occasion of the celebration of the centennial 
anniversary of the Academy on October 11, 1899, Pro- 
fessor, later Governor, Baldwin, the president of the 
Academy, discusses this subject in some detail. He says 
in part: 

To support his [Silliman’s] undertaking, a vote had been 
passed in February [1818], ‘‘that the Committee of Publication 
may allow such of the Academy’s papers as they think proper, 
to be published in Mr. Silliman’s Scientific Journal.’’ 

Free use was made of this authority, and a large part of the 
contents of the Journal was for many years drawn from this 
source. In some cases this fact was noted in publication ;? but 
In most 1t was not. . 


*The following footnote accompanies the opening article of the first 
volume of the Journal. ‘‘From the MS. papers of the Connecticut Acad- 
emy, now published by permission.’’? Similar notes appear elsewhere. 


30 Dana—American Journal of Science, 1818-1918. 


In 1826, when the Journal was in great need of financial sup- 
port, the Academy further voted to pay for a year the cost of 
printing such of its papers as might be published, in it. In 
Baldwin’s Annals of Yale College, published in 1831, it is 
described as a publication ‘‘honorable to the science of our 
common country,’’ and having ‘‘an additional value as being 
adopted as the acknowledged organ of the Connecticut Academy 
of Arts and Sciences.’’ | 


‘Many active campaigns were carried on over the 
country through paid agents to obtain new subscribers 
for the Journal and it was doubtless due to these efforts 
that the nominal subscription list was, at times, as 
already noted, relatively large as compared with that of a 
later date. The new subscribers in many cases, however, 
did not remain permanently interested, often failed to 
pay their bills, and the uncertain and varying demand 
upon the supply of printed copies was doubtless one 
- reason why many single numbers became early out of 
print. 

An interesting sidelight is thrown upon the efforts of 
Silliman to interest the public in his work, at its begin- 
ning, by a letter to the editor from Thomas J efferson, 
then seventy-five years of age. The writer is indebted to 
Mr. Robert B. Adam of Buffalo for a copy of this letter 
and its interest justifies its being reproduced here entire. 
The letter is as follows: 


Monticello, Apr. 11. 718. 

Sir 

The unlucky displacement of your letter of Mar 3 has been 
the cause of delay in my answer. altho’ I have very generally 
withdrawn from subscribing to or reading periodical publica- 
tions from the love of rest which age produces, yet I willingly 
subseribe to the journal you propose from a confidence that the 
talent with which it will be edited will entitle it to attention 
among the things of select reading for which alone I have time 
now left. be so good as to send it by mail, and the receipt of 
the 1st number will be considered as announcing that the work 
is commenced and the subscription money for a year shall: be 
forwarded. Accept the assurance of my great esteem and 
respect. 


Th. Jefferson 
Professor Silliman. 


Dana—American Journal of Scrence, 1818-1918. 31 


Contributors.—An interesting summary is also given 
by Silliman of the contributors to the Journal and the 
extent of their work (vol. 50, pp. xii, xiii); he says: 


We find that there have been about 600 contributors of orig- 
inal matter to the Journal, and we have the unexpected satis- 
faction of believing that probably five-sixths of them are still 
living; for we are not certain that more than fifty are among 
the dead; of perhaps fifty more we are without information, 
and if that additional number is to be enrolled among the ‘‘stel- 
ligeri,’’ we have still 500 remaiing. Among them are not a 
few of the veterans with whom we began our career, and several 
of these are still active contributors. Shall we then conclude 
that the peaceful pursuits of knowledge are favorable to long 
life? This we think is, cewteris paribus, certainly true: but in 
the present instance, another reason can be assigned for the 
large amount of survivorship. As the Journal has advanced 
and death has removed its scientific contributors. younger men 
and men still younger, have recruited the ranks, and volunteers 
have enlisted in numbers constantly increasing, so that the 
flower of the host are now in the morning and meridian of life. 

We have been constantly advancing, like a traveller from the 
equinoctial towards the colder zones,—as we have increased our 
latitude, stars have set and new stars have risen, while a few 
planetary orbs visible in every zone, have continued to cheer us 
on our course. 

The number of articles, almost exclusively original, contained 
in the Journal is about 1800, and the Index will show how many 
have been contributed by each individual; we have doubtless 
included in this number some few articles republished from 
foreign Journals—but we think they are even more than coun- 
terbalanced by original communications without a name and by 
editorial articles, both of which have been generally omitted in 
the enumeration. 

Of smaller articles and notices in the Miscellany, we have not 
made any enumeration, but they evidently are more numerous 
than the regular articles, and. we presume that they may amount 
to at least 2500. 

Of party, either in politics or religion, there is no trace in 
our work; of personalities there are none, except those that 
relate to priority of claims or other rights of individuals. Of 
these vindications the number is not great, and we could heartily 
have wished that there had been no oceasion for any. 


General Scope of Articles—Many references will be 
found in the chapters following which throw light upon 
the character and scope of the papers published in the 
Journal, particularly in its early years; a few additional 
statements here may, however, prove of interest. 


32 Dana—American Journal of Science, 1818-1918. 


One feature that is especially noticeable is the frequent 
publication of articles planned to place before the read- 
ers of the Journal in full detail subjects to which they 
might not otherwise have access. These are sometimes 
translations; sometimes republications of articles that 
had already appeared in English periodicals; again, 
they are exhaustive and critical reviews of important 
memoirs or books. The value of this feature in the early 
history of the Journal, when the distribution of scientific 
literature had nothing of the thoroughness characteristic 
of recent years, is sufficiently obvious. 

It is also interesting to note the long articles of geo- 
logical description and others giving lists of mineral or 
botanical localities. Noteworthy, too, is the attempt to 
keep abreast of occurring phenomena as in the many ~ 
notes on tornadoes and storms by Redfield, Loomis, ete. ; 
on auroras at different localities; on shooting stars by 
Herrick, Olmstead and others. 

The wide range of topics treated of is quite in accord- 
ance with the plan of the editor as given on an earlier 
page. Some notes, taken more or less at random, may 
serve to illustrate this point. An extended and quite 
technical discussion of ‘‘Musical Temperament’’ opens 
the first number (1, pp. 9-35) and is concluded in the same 
volume (pp. 176-199). An article on ‘‘Mystery’’ is given 
by Mark Hopkins A.M., ‘‘late a tutor of Williams Col- 
lege’? (13, 217, 1828). There is an essay on ‘‘Gypsies”’ 
by J. Griscom (from the Revue Encyclopédique) in vol- 
ume 24 (pp. 342-345, 1833), while some notes on American 
gypsies are added in vol. 26 (p. 189, 1834). The ‘‘divin- 
ing rod’’ is described at length in vol. 11 (pp. 201-212, 
1826), but without giving any comfort to the credulous ; 
_on the contrary the last paragraph states that ‘‘the pre- 
tensions of diviners are worthless, etc.’’ A long article 
by J. Finch on the forts of Boston harbour appeared 
in 1824 (8, 338-348); the concluding paragraph seems 
worthy of quotation. 


‘‘Many centuries hence, if despotism without, or anarchy 
within, should cause the republican institutions of America to 
fade, then these fortresses ought to be destroyed, because they 
would be a constant reproach to the people; but until that 
period, they should be preserved as the noblest. monuments of 
liberty.’’ 


Dana—American Journal of Science, 1818-1918. 33 


The promise to include the fine arts is kept by the pub- 
heation of various papers, as of the Trumbull painting's 
(16, 163, 1829); also by a series of articles on ‘‘architec- 
ture in the United States’’ (17, 99, 1830; 18, 218, 220, 
1830) and others. Quite in another line is the paper by 
J. W. Gibbs (33, 324, 1838) on ‘‘Arabic words in 
Eneglish.’’ A number of related linguistic papers by the 
same author are to be found in other volumes. Papers 
in pure mathematics are also not infrequent, though 
now not considered as falling within the field of the 
Journal. 

Applied science takes a prominent place through all the 
volume of the First Series. An interesting paper is that 
on Eli Whitney, containing an account of the cotton gin; 
this is accompanied by an excellent portrait (21, 201-264, 
1832). The steam engine and its application are repeat- 
edly discussed and in the early volumes brief accounts 
are given of the early steamboats in use; for example, 
between Stockholm and St. Petersburg (2, 347, 1820) ; 
Trieste and Venice (4, 377, 1822); on the Swiss Lakes 
(6, 385, 1823). The voyage of the first Atlantic steam- 
boat, the ‘‘Savannah,’’ which crossed from Savannah 
to Liverpool in 1819, is described (38, 155, 1840); men- 
tion is also made of the ‘‘first iron boat’’ (3, 371, 1821; 
5, 396, 1822). A number of interesting letters, on 
‘“‘Steam Navigation’’ are given in vol. 35, 160, 162, 332, 
3308, 306; some of the suggestions seem very quaint, 
viewed in the light of the experience of to-day. 

A very early form of explosive engine is described at 
length by Samuel Morey (11, 104, 1826); this is an article 
that deserves mention in these days of gasolene motors. 
Even more interesting is the description by Charles Gris- 
wold (2, 94, 1820) of the first submarime invented by 
David Bushnell and used in the Revolutionary War in 
August, 1776. An account is also given of a dirigible 
balloon that may be fairly regarded as the original ances- 
tor of the Zeppelin (see 11, 346, 1826). The whole sub- 
ject of aérial navigation is treated at length by H. Strait 
(25, pp. 25, 26, 1834) and the expression of his hopes for 
the future deserve quotation: 

‘‘Conveyance by air can be easily rendered as safe as by 
water or land, and more cheap and speedy, while the universal 
and uniform diffusion of the air over every portion of the 
earth, will render aérial navigation preferable to any other. To 


Am. Jour. Sci1.—FourtH Srries, Vou. XLVI, No. 271.—Juty, 1918. 
2 


en 


34. Dana—American Journal of Science, 1818-1918. 


carry it into effect, there needs only an immediate appeal on a 
sufficiently large scale, to experiment; reason has done her part, 
when experiment does hers, nature will not refuse to sanction the 
whole. Aerial navigation will present the works of nature in 
all their charms; to commerce and the diffusion of knowledge, 
it will bring the most efficient aid, and it can thus be rendered 
serviceable to the whole human family.’’ 


A subject of quite another character is the first discus- 
sion of the properties of chloroform (chloric ether) and 
its use as an anesthetic (Guthrie, 21, 64, 405, 1832; 
22, 105, 1832; Levi Ives, 21, 406). Further interesting 
communications are given of the first analyses of the gas- 
tric juice and the part played by it in the process of 
digestion. Dr. William Beaumont of St. Louis took 
advantage of a patient who through a gun-shot wound 
was left with a permanent opening into his stomach 
through which the gastric juice could be drawn off. The 
results of Dr. Beaumont.and of Professor Robley Dungli- 
son, to whom samples were submitted, are given in full 
in the hfe of Beaumont by Jesse 8S. Myer (St. Louis, 
1912). The interest of the matter, so far as the Journal 
is concerned, is chiefly because Dr. Beaumont selected 
Professor Silliman as a chemist to whom samples for 
examination were also submitted. An account of Silli- 
man’s results is given in the Beaumont volume referred 
to (see also 26, 193, 1834). Desiring the support of a 
chemist of wider experience in organic analysis, he also 
sent a sample through the Swedish consul to Berzelius in 
Stockholm. After some months the sample was received 
and it is interesting to note in a perfectly fresh condi- 
tion; it is to be regretted, however, that the Swedish 
chemist failed to add anything to the results already 
obtained in this country (27, 40b, 1835). 

The above list, which might be greatly extended, seems 
to leave little ground for the implied criticism replied to 
by Silliman as follows (16, p. v, 1829): 


A celebrated scholar, while himself an editor, advised me, in - 
a letter, to introduce into this Journal as much ‘‘readable’’ 
matter as possible: and there was, pretty early, an earnest but 
respectful recommendation in a Philadelphia paper, that Litera- 
ture, in imitation of the London Quarterly Journal of Science, 
&c. should be in form, inscribed among the titles of the work. 


Dana—American Journal of Science, 1818-1918, 35 


Tue SEconD, THIRD AND FourRTH SERIES. 


The Seconp Series of the Journal, as already stated, 
began with January, 1846. Up to this time the publica- 
tion had been a quarterly or two volumes annually of two 
numbers each. From 1846 until the completion of an 
additional fifty volumes in 1871, the Journal was made a 
bimonthly, each of the two yearly volumes having three 
numbers each. Furthermore, a general index was given 
for each period of five years, that is for every ten 
volumes. 

Much more important than this change was the addi- 
tion to the editorial staff of James Dwight Dana, Suilli- 
man’s son-in-law. Dana returned from the four-years 
eruise of the Wilkes Exploring Expedition in 1842; he 
settled in New Haven, was married in 1844, and in 1850 
was appointed Silliman professor of Geology in Yale 
College. He was at this time actively engaged in writ- 
ing his three quarto reports for the Expedition and 
hence did not begin his active professional duties in Yale 
College until 1856. Part of his inaugural address was 
quoted on an earlier page. 

Dana had already performed the severe labor of pre- 
paring the complete index to the First Series, a volume 
of about 350 pages, finally issued in 1847. From the 
beginning of the Second Series he was closely associated 
with his brother-in-law, the younger Silliman. Later the 
editorial labor devolved more and more upon him and the 
larger part of this he carried until about 1890. His work, 
was, however, somewhat interrupted during periods of ill 
health. This was conspicuously true during a year’s 
absence in Europe in 1859-60, made necessary in the 
search for health; during these periods the editorial 
responsibility rested entirely upon the younger Silliman. 
Of Dana’s contributions to science in general this is not 
the place to speak, nor is the present writer the one to 
dwell in detail upon his work for the Journal. This sub- 
ject is to such an extent involved in the history of geology 


and zoology, the subjects of several succeeding chapters, . 


that it is adequately presented in them. 

It may, however, be worth stating that in the pinliew 
raphy accompanying the obituary ‘notice of Dana (49, 
329-356, 1895) some 250 titles of articles in the Journal 
are enumerated; these aggregate approximately 2800 


| 


36 Dana—American Journal of Science, 1818-1918. 


pages. The number of critical notes, abstracts, book 
reviews, ete., could be also given, were it worth while, but 
what is much more significant in this connection, than 
their number or aggregate length, is the fact that these 
notices are in a large number of cases—like those of Gray 
in botany—minutely critical and original in matter. 
They thus give the writer’s own opinion on a multitude 
of different subjects. It was a great benefit to Dana, as 
it was to science also, that he had this prompt means at 
hand of putting before the public the results of his active 
brain, which continued to work unceasingly even in times 
of health prostration. 

This may be the most convenient place to add that as 
Dana became gradually less able to carry the burden of 
the details involved in editing the Journal in addition to 
his more important scientific labors, particularly from 
1890 on, this work devolved more and more upon his son, 
the present editor, whose name was added to the editorial 
staff in 1875, with volume 9, of the Third Series. The 
latter has served continuously until the present time, 
with the exception of absences, due to ill health, in 1893-94 
and in 1903; during the first of these Professor Henry S. 
Willams and during the second Professor H. KH. Greg- 
ory occupied the editorial chair. 


The Tuirp Serres began in 1871, after the completion 
of the one-hundredth volume from the beginning in 1818. | 
At this date the Journal was made a monthly and as such 
it remains to-day. Fifty volumes again completed this 
series, which closed in 1895. 

The FourrH Srrizs began with January, 1896, and the 
present number for July, 1918, is the opening one of the 
forty-sixth volume or, in other words,—the one hundred 
and ninety-sixth volume of the entire issue since 1818. 
The Fourth Series, according to the precedent estab- 
lished, will end with 1920. 


Associate Editors —In 1851 the new policy was intro- 
duced of adding ‘‘ Associate Editors’’ to the staff. The 
first of these was Dr. Wolcott Gibbs of Cambridge. He 
began his duties with the eleventh volume of the Second 
Series in 1851 and continued them with unceasing care 
and thoroughness for more than twenty years. Ina note 
dated Jan. a 1851 (11, 105), he says: 


Dana—American Journal of Science, 1818-1918. 37 


It is my intention in future to prepare for the columns of this 
Journal abstracts of the more important physical and chemical 
memoirs contained in foreign scientific journals, accompanied 
by references, and by such critical observations as the occasion 
may demand. Contributions of a similar character from others 
will of course not be excluded by this arrangement, but I shall 
hold myself responsible only for those notices which appear 
over my initials. 


The departments covered by Dr. Gibbs, in his excellent 
monthly contributions, embraced chemistry and physics, 
and these subjects were carried together until 1873 when 
they were separated and the physical notes were fur- 
nished, first by Alfred M. Mayer and later successively 
by E. C. Pickering (from 1874), J. P. Cooke (from 1877), 
and John Trowbridge (from 1880). The first instalment 
of the long series of notes in chemistry and chemical 
physics by George F. Barker, was printed in volume 50, 
1870. He came in at first to occasionally relieve Dr. 
Gibbs, but soon took the entire responsibility. His name 
was placed among the associate editors on the cover in 
1877 and two years later Dr. Gibbs formally retired. It 


may be added that from the beginning in 1851 to the 


present time, the notes in ‘‘Chemistry and Physics’’ have 
been continued almost without interruption. 

The other departments of science have been also fully 
represented in the notes, abstracts of papers pub- 


lished, book notices, ete., of the successive numbers, but 


as with the chemistry and physics the subject of botany 
was long treated in a similar formal manner. For the 
notes in this department, the Journal was for many years 
indebted to Dr. Asa Gray, who became associate editor in 
1853, two years after Gibbs, although he had been a 
not infrequent contributor for many years previously, 
Gray’s contributions were furnished with great regu- 
larity and were always critical and original in matter. 
They formed indeed one of the most valuable features 
of the Journal for many vears; as botanists well appre- 
ciate, and, as Professor Goodale has emphasized in his 
chapter on botany, Gray’s notes are of vital importance 
in the history of the development of his subject. With 
Gray’s retirement from active duty, his colleague, 
George W. Goodale, took up the work in 1888 and in 1895 
Wilham G. Farlow, also of Cambridge, was added as an 
associate editor in cryptogamic botany. At this time, 


ae + re 


——— A AR et 


38 Dana—American Journal of Scrence, 1818-1918. | 


however, and indeed earlier, the sphere of the Journal 
had unavoidably contracted and botany perforce ceased. 
to occupy the prominent place it had long done in the 
Journal pages. 

This is not the place to present an appreciation of the 
truly magnificent work of Asa Gray. It may not be out 
of place, however, to call attention to the notice of Gray 
written for the Journal by his life-long friend, James D. 
Dana (35, 181, 1855). The opening paragraph is as 
follows: | 3 

‘‘Our friend and associate, Asa Gray, the eminent botanist 
of America, the broad-minded student of nature, ended his life 
of unceasing and fruitful work on the 30th of January last. 
For thirty-five years he has been one of the editors of this Jour- 
nal, and for more than fifty years one of its contributors; and 
through all his communications there is seen the profound and 
always delighted student, the accomplished writer, the just and 
genial critic, and as Darwin has well said, ‘The lovable man.’ ’’ 


The third associate editor, following Gray, was Louis 
Agassiz, whose work for science, particularly in his 
adopted home in this country, calls for no praise here. 
His term of service extended from 1853 to 1866 and, par- 
ticularly in the earlier years, his contributions were nu- 
merous and important. The next gentleman in the lst 
was Waldo I. Burnett, of Boston, who served one year 
only, and then followed four of Dana’s colleagues in New 
Haven, of whose generosity and able assistance it would 
be impossible to say too much. These gentlemen were 
Brush in mineralogy; Johnson in chemistry, particularly 
on the agricultural side; Newton in mathematics and 
astronomy, whose contributions will be spoken of else- 
where; and Verrill—a student of Agassiz—in zoology. 

All of these gentlemen. besides their frequent and 
important original articles, were ever ready not only to 
give needed advice, but also, to furnish brief communt- 
cations, abstracts of papers and book reviews, and other- 
wise to aid in the work. Verrill particularly furnished 
the Journal a long list of original and important papers, 
chiefly in systematic zoology, extending from 1865 
almost down to the present year. His abstracts and 
book notices also were numerous and trenchant and it is 
not too much to say that without him the Journal never 
eould have filled the place in zoology which it so long 
held. Much later the list of New Haven men was 


Dana—American Journal of Science, 1818-1918. 39 


increased by the addition of Henry S. Williams (1894), 
and O. C. Marsh (1895). 

Of the valuable work of those more or less closely asso- 
ciated in the conduct of the Journal at the present time, 
it would not be appropriate to speak in detail. It must 
suffice to say that the services rendered freely by them 
have been invaluable, and to their aid is due a large part 
of the success of the Journal, especially since the Fourth 
Series began in 1896. But even this statement is inade- 
quate, for the editor-in-chief has had the generous assist- 
ance of other gentlemen, whose names have not been 
placed on the title page, and who have also played an 
important part in the conduct of the Journal. This 
policy, indeed, is not a matter of recent date. Very 
early in the First Series, Professor Griscom of Paris, as 
already noted, furnished notes of interesting scientific 
discoveries abroad. Other gentlemen have from time to 
time acted in the same capacity. The most prominent of 
them was Professor Jerome Nickles of Nancy, France, 
who regularly furnished a series of valuable notes on 
varied subjects, chiefly from foreign sources, extending 
from 1852 to 1869. On the latter date he met an untimely 
death in his laboratory in connection with experiments 
upon hydrofluoric acid (47, 434, 1869). 

It may be added, further, that one of the striking 
features about the Journal, especially in the earlier half 
century of its existence, is the personal nature of many 
of its contributions, which were very frequently in the 
form of letters written to Benjamin Silliman or J. D. 
Dana. This is perhaps but another reflection of the 
extent to which the growth of the magazine centered 
around these two men, whose wide acquaintance and 
broad scientific repute made of the Journal a natural 
place to record the new and interesting things that were 
being discovered in science. 

The following list gives the names and dates of ser- 
vice, as recorded on the Journal title pages, of the gen- 
tlemen- formally made Associate Editors: 


Miolcott Gapbs: vse... eS ile tsotte (3) 18, 1879 
Pre Gane ase tl. 25) fF, Eeloriehs 99 4% >.34 4887 
Waugh Neassin! ya. Pele. alo elena. ip (2)? 4 1866 
Rvaldo ies Bumnetie aes eh. dap aOR oe cas LT)! PBS. 
Geer. jibsmishe wi o6c/. . uae Peo OGay 146(o)) LO 1809 


Sanminel Wed OhNSON:. . 2 sn. 2 fea lousuery Sy Lee deo 


a een 


40 Dana—American Journal of Science, 1818-1918. 


Elubert: Av Newton 251" ae be 7p (2) 38, 1864 to (4) 1, 1896 
Addison’ i: AVviervililec 0 we. Pad, 1869 | 
Alfred iii Mia eet ce cee ce (3)...b, 1878 ete 7G) Gas is © 
Hdward, C. Pickerino 6.00 2 e. Sy 1, IOTA ee dene ahesrg) 
Georeeeih sbarker Us tjhs sec 14, 1ST a ae a0 
Osialiicr:: COOKE... 0... ae. see a EST Ga eeese 
Joume Mrowbrmdee. onc. 5c. = KOS LS Sh 

George W. Goodale 202.45. 2. bh eae disiste: 

Ffenry *S2nw ibiamis® 220200 tee ‘47, 1894 
Henry, P.: Bowditel= 55.2020 ‘S| 49. 1895 tte (i Saaisgs 
Wallhiam: Go Warlows }:505 i. oo. 2 ‘© 49. 1895 | 
Othniel C. Manshvsape = Weercn. ‘49, 1895: tonG’) 6, se9 
Henry A Rowland: 3... se S27. (4)... 1, 1896 "742" Nee 300 
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PRESENT AND EF uTuURE CONDITIONS. 


The field to be oceupied by the ‘‘ American Journal of 
Science and Arts,’’ as seen by its founder in 1818 and 
presented by him in the first number, as quoted entire on 
an earlier page, was as broad as the entire sphere of 
science itself. It thus included all the departments of 
both pure and applied science and extended even to music 
and fine arts also. As the years went by, however, and 
the practical applications of science greatly iecreased, 
technical journals started up, and the necessity of culti- 
vating this constantly expanding field diminished. It 
was not, however, until January, 1880, that ‘‘the Arts’’ 
ceased to be a part of the name by which the Journal 
was known. 

About the same date also—or better a little earlier— 
began an increasing development of scientific research, 
particularly as fostered by the graduate schools of our 
prominent universities. The full presentation of this 
subject would require much space and is indeed unneces- 
sary as the main facts must be distinct in the mind of the 
reader. It is only right, however, that the large part 
played in this movement by the Johns Hopkins Univer- 
sity (founded in 1876) should be mentioned here. 

As a result of this movement, which has been of great 
benefit in stimulating the growth of science in the 


Dana—American Journal of Science, 1818-1918. 41 


country, many new journals of specialized character have 
come into existence from time to time. Further local- 
ization and specialization of scientific publication have 
resulted from the increased activity of scientific societies 
and academies at numerous centers and the springing 
into existence thereby of new organs of publication 
through them, as also through certain of the Government 
Departments, the Carnegie Institution, and certain uni- 
versities and museums. 

As bearing upon this subject, the following list of the 
more prominent scientific periodicals started in this 


country since 1867 is not without interest: 


1867— American Naturalist. 

1875— . Botanical Bulletin; later Botanical Gazette. 
1879-1913. American Chemical Journal. 
1880-1915. School of Mines Quarterly. 

1883— Science. 

1885-— Journal of Heredity. 

1887— Journal of Morphology. 

1887-1908. Technology Quarterly. 

1888-1905. American Geologist. 

1891- Journal of Comparative Neurology. 
1893- Journal of Geology. 

1893— Physical Review. 

1895-— Astrophysical Journal. 

1896- Journal of Physical Chemistry. 
1896— . Terrestrial Magnetism. 

1897-1899. Zoological Bulletin; followed by 
1900- Biological Bulletin. 

1901- .. American Journal of Anatomy. 
1904— . Journal of Experimental Zoology. 
1905- . Economic Geology. 

1906- . Anatomical Record. 

1907— . Journal of Economic Entomology. 
1911- . Journal of Animal Behavior. 
1914— . American Journal of Botany. 
1916— . Genetics. 

1918- . American Journal of Physical Anthropology. 


The result of the whole movement has been of neces- 
sity to-narrow, little by little, the sphere of a general 
scientific periodical such as the Journal has been from 
the beginning. The exact change might be studied in 
detail by tabulating as to subjects the contents of succes- 
sive volumes, decade by decade, from 1870 down. It is 
sufficient, here, however, to recognize the general fact 
that while the number of original papers published in the 
periodicals of this country, in 1910, for example, was very 


42 Dana—American Journal of Science, 1818-1918. 


many times what it was in 1825, a large part of these 
have naturally found their home in periodicals devoted 
to the special subject dealt with in each case. That this 
movement will continue, though in lessened degree now 
that the immediate demand is measurably satisfied, is to 
be expected. At the same time it has not seemed wise, at 
any time in the past, to formally restrict the pages of the 
Journal to any single group of subjects. The future is 
before us and its problems will be met as they arise. At 
the moment, however, there seems to be still a place for a 
scientific monthly sufficiently broad to include original 
papers of important general bearing even if special in 
immediate subject. In this way it would seem that 
‘‘Siliman’s Journal’’ can best continue to meet the 
ideals of its honored founder, modified as they must be to 
meet the change of conditions which a century of scien- 
tific investigation and growth have wrought. Incident- 
ally it is not out of place to add that a self-supporting, 
non-subsidized scientific periodical may hope to find a 
larger number of subscribers from among the workers in 
science and the libraries if it is not too restricted in scope. 

The last subject touched upon introduces the essential 
matter of financial support without which no monthly 
publication can survive. With respect to the periodicals 
of recent birth, listed above, it is safe te say that some 
form of substantial support or subsidy—often very gen- 
erous—is the rule, perhaps the universal one. This has 
never been the case with the American Journal. The 
liberality and broad-minded attitude of Yale Coilege in 
the early days, and of the Yale University that has devel- 
oped from it, have never been questioned. At the same 
time the special conditions have been such as to make it 
desirable that the responsibility of meeting the financial 
requirements should be carried by the editors-in-chief. 
At present the Yale Library gives adequate payment for 
certain publications received by the Journal in exchange, 
though for many years they were given to it as a matter 
of course, free of charge. Beyond this there is nee 
approaching a subsidy. 

The difficulties on the financial side met with by the ase 
Silliman have been suggested, although not adequately 
presented, in the various statements quoted from early 
volumes. The same problems in varying degree have 
continued for the past sixty years. Since 1914 they have 
been seriously aggravated for reasons that need not be 


° 
9 


Dana—American Journal of Science, 1818-1918, 48 


enlarged upon. Prior to that date the subscription list 
had, for reasons chiefly involved in the development of 
special journals, been much smaller than the number 
estimated by Silliman, for example, in volume 50 (p. xiv), 
although there has been this partial compensation that 
the considerable number of well-established libraries on 
the subscription list has meant a greater degree of sta- 
bility and a smaller proportion of bad accounts. The 
past four years, however, the Journal, with all simi- 
lar undertakings here and elsewhere, has been compelled 
to bear its share of the burden of the world war in dimin- 
ished receipts and greatly increased expenses. It is 
gratifying to be able to acknowledge here the generosity 
of the authors, or of the laboratories with which they 
have been connected, in their willingness not infrequently 
to give assistance, for example, in the payment of more 
or less of the cost of engravings, or in a few special cases 
a large portion of the total cost of publication. In this 
way the problem of ways and means, constantly before 
the editor who bears the sole responsibility, has been 
simplified. 

It should also be stated that as those immediately 
interested have looked forward to the present anniver- 
sary, 1t has been with the hope that this occasion might be 
an appropriate one for the establishment of a ‘‘Silliman 
Fund’’ to commemorate the life and work of Benjamin 
Silliman. The income of such a fund would lift from 
the University the burden that must unavoidably fall 
upon it when the responsibility for the conduct of the 
Journal can no longer be carried by members of the fam- 
ily including the editor and—as in years long past—a 
silent partner whose aid on the business side has been 
essential to the efficiency and economy of the enterprise. 
Present conditions are not favorable for such a move- 
ment, although some thing has been already accomplished 
in the desired direction. At the present time every 
patriotic citizen must feel it his first duty to give his sav- 
ings as well as his spare income to the support of the 
National Government in the world struggle for freedom 
in which it is taking part. But, whatever the exact con- 
dition of the future may be, it cannot be questioned that 
the Journal founded by Benjamin Silliman in 1818 will 
survive and will continue to plav a vital part in the sup- 
port and further development of science. 

The present year of 1918 finds the world at large, and 


———— —— : SURE SS SSeS hss steals selesestpsnssnessemepesonmeemmsmomememennsisee 
a ES eT 


44 Dana—American Journal of Science, 1818-1918. 


with it the world of science, painfully crushed beneath the 
overwhelming weight of a world war of unprecedented 
severity. The four terrible years now nearly finished 
have seen a fearful destruction of life and property which 
must have a sad influence on the progress of science for 
many years to come. Only in certain restricted lines has 
there been a partial compensation in the stimulating 
influence due to the immediate necessities connected with 
the great conflict. One hundred years ago ‘‘the reign of 
war’’ was keenly in the mind of the editor in beginning 
his work, but for him, happily, the long period of the 
Napoleonic wars was already in the past, as also the brief 
conflict of 1812, in which this country was engaged and in 
which Silliman himself played a minor part. We, too, 
must believe, no matter how serious the outlook of the 
present moment, that a fundamental change will come in 
the not distant future; the nations of the world must 
sooner or later turn once more to peaceful pursuits and 
the scientific men of different races must become again 
not enemies but brothers engaged in the common cause 
of uplifting human life. The peace that we look forward 
to to-day is not for this country alone, but a peace which 
shall be a permanent blessing to the entire world for 
ages to come. 


Norr.—The portrait which forms the frontispiece of 
the present number has been reproduced from the plate 
in volume 50 (1847). The original painting was made by 
H. Willard in 1835, when Silliman was in Boston 
engaged in delivering the Lowell lectures; he was then 
nearly fifty-six years of age. The engraving, as he 
states elsewhere, was made from this painting for the 
Yale Literary Magazine, and was published in the num- 
ber for December, 1839. 

It is interesting to quote the remarks with which the 
editor introduces the portrait (50, xviii, 1847). He says: 


The portrait prefixed to this volume was engraved for a very 
different purpose and for others than the patrons of this Jour- 
nal. It has been suggested by friends, whose judgment we are 
accustomed to respect, that it ought to find a place here, since it 
is regarded as an authentic, although, perhaps, a rather austere 
resemblance. In yielding to this suggestion, it may be sufficient 
to quote the sentiment of Cowper on a similar occasion, who 
remarked—‘‘that after a man has, for many years, turned his 
mind inside out before the world, it is only affectation to attempt 
to hide his face.’’ 


Charles Schuchert—Historical Geology, 1818-1918. 45 


Art. Il.—A Century of Geology—The Progress of His- 
torical Geology in North America; by CHaRLES 
ScHUCHEBRT. 


INTRODUCTION. 


The American Journal of Science, ‘‘one of the greatest 
influences in American geology,’’ founded in 1818, has 
published a little more than 92,000 pages of scientific mat- 
ter. Of geology, including mineralogy, there appear to be 
upward of 20,000 pages. What a vast treasure house of 
geologic knowledge is stored in these 194 volumes, and 
how well the editors have lived up to their proposed 
‘‘plan of work’’ as stated in the opening volume, where 
Silliman says: ‘‘It is designed as a deposit for original 
American communications’’ in ‘‘the physical sciences 

. . and especially our eet and geology’’ (1, v, 
1818)! Not only is it the oldest continuously published 
scientific journal of this country, but it has proved itself 
to be ‘‘perhaps the most important geological periodical 
in America’’ (Merrill). It is impossible to adequately 
present in this memorial volume of the Journal the con- 
tents of the articles on the geological sciences. 

Editor Silliman was not only the founder of the Jour- 
nal, but the generating center for the making of 
geologists and promoting geology during the rise of this 
science in America. For nearly three decades, the work- 
ers came to him for counsel and help, and he had a kind 
paternal word for them all. This influence is also shown 
in the many letters which were addressed to him, and 
which he published in the Journal. <A similar influence, 
paternal care, and constructive criticism were continued 
by James D. Dana, and especially in his earlier career 
as editor. 

Not including mineralogy, there are in the Journal 
upward of 1500 distinct articles on geology. Of these, 
over 400 are on vertebrate paleontology, about 325 on 
invertebrate paleontology, and 90 on paleobotany. Of 
articles bearing on historical geology there are about 160, 
and on stratigraphic geology more than 360. In addition 
to all this, there are more than 2000 pages of geologic 
matter relating to books and of letters communicated to 
the editors Silliman and Dana. We may summarize with 


46 Charles Schuchert—Historical Geology, 1818-1918. 


Doctor Merrill’s statement in his well-known Contribu- 
tions to the History of American Geology: 


‘‘From its earliest inception geological notes and papers 
occupied a prominent place in its pages, and a perusal of the 
numbers from the date of issue down to the present time will, 
alone, afford a fair idea of the gradual progress of American 
geology.’’ 


Before presenting a synopsis of the more important 
steps in the progress of historical geology in America, it 
will be well to introduce a rapid survey of the rise of 
geology in Europe, for, after all, American geology grew 
out of that of England, France and Germany. This 
dependence was conspicuously true during the first 
four decades of the previous century. With the rise of 
the first New York State Survey (1836-1843) and that 
of Pennsylvania (1836-1844, 1858), American geology 
became more or less independent of Europe. Finally, 
this article will conclude with a survey of the rise of 
paleometeorology, paleogeography, evolution, and inver- 
tebrate paleontology. 


THe RIsE oF GEOLOGY IN EUROPE. 


Mineral Geology.—The geological sciences had their 
rise in the study of minerals as carried on by the German 
chemist and physician George Bauer (1494-1555), better - 
known as Agricola. Bauer originated the critical study 
of minerals, but did not distinguish his ‘‘fossilia,’’ the 
remains of organisms, from the inorganic crystal forms. 
Mineral geology endured until the close of the eighteenth 
century. 

Cosmogonists.—Then came the expounders of the 
earth’s origin, the cosmogonists of the sixteenth to the 
end of the eighteenth centuries. The fashion of this 
time was to write histories of the earth derived out of 
the imagination. 

Earliest Historical Geology—Even though Giovanni 
Arduino (1713-1795) of Padua was not the first to 
classify the rocks into three series according to their 
age, he did this more clearly than any one else before his 
time. The rocks about Verona he grouped in 1759 into 
Primary, Secondary, Tertiary, and Volcanic. This 
three-fold classification came into general use, “een 
modified with time. 


Charles Schuchert—Historical Geology, 1818-1918. 47 


Karly in the nineteenth century it had become plain 
that formations of very varying ages were included in 
each one of the three series. Through the study of the 
fossils and the recognition of the fact that mountain 
ranges have been raised at various times, causing 
younger fossiliferous strata to take on the characters of 
the Primary, it was seen that these terms of Arduino had 
lost their original significance. 

The first one to describe in detail a local stratigraphic 
Sequence was Johann Gottlob Lehmann (died 1767). 
In 1756 he published ‘‘one of the classics of geological 
literature,’’ distinguishing clearly thirty successive sedi- 
mentary deposits, some of which he said had fossils, but 
he did not use them to distinguish the strata. 

What Lehmann did for the Permian system, George 
Christian Fuchsel (1722-1773) did even better for the 
Triassic of Thuringia, in 1762 and 1773. He pointed out 
not only the sequence, but also how the gently inclined 
strata rest upon the older upturned masses of the moun- 
tains; also that some formations have only marine fos- 
sils, while others have only terrestrial forms and thus 
indicate the proximity of land. The deformed strata he 
thought had fallen into the hollows within the earth, 
great caverns that had also consumed much of the 
oceanic waters and had in so doing greatly lowered 
the sea-level. It was Fuchsel who first introduced the 
theory of universal formations, and who defined the term 
formation, using it as we now do, system or periou. 
Even though Lehmann and Fichsel showed that there 
was a definite order and process in the formation of the 
earth’s crust, their example was barren of followers until 
the beginning of the eighteenth century. 

Wernerian Geology or Geognosy.—We come now to 
the time of Abraham Gottlob Werner (1749-1817), who 
from 1775 to 1817 was professor of mining and mineral- 
ogy in the Freiberg Academy of Mines. Geikie, in his 
most interesting Founders of Geology, says that Werner 
‘‘bulks far-more largely in the history of geology than 
any of those with whom up to the present we have been 
concerned—a man who wielded an enormous author- 
ity over the mineralogy and geology of his day.’’ 
*‘ Although he did great service by the precision of his 
lithological characters and by his insistence on the doc- 
trine of geological succession, yet as regards geological 


48 Charles Schuchert—Historical Geology, 1818-1918. 


theory, whether directly by his own teaching, or indi- 
rectly by the labors of his pupils and followers, much of 
his influence was disastrous to the higher interests of 
geology.’’ 

Werner arranged the crust of the earth ines a series of 
formations, as had been done previously by Lehmann 
and Fiichsel, and one of his fundamental postulates was 
that all rocks were chemically precipitated in the ocean 
as ‘‘universal formations.’’ For this reason Werner’s 
school were called the Neptunists. Nowhere, however, 
did he explain how and where the deep and primitive 
ocean had disappeared. 

According to Werner, the first formed or oldest rocks 
were the chemically deposited Primitive strata, including 
granite and other igneous and metamorphic rocks. On 
these followed the Transition rocks, the earliest sedi- 
ments of mechanical origin, and above them the Floetz 
rocks, a term for the horizontal stratified rocks. These 
last he said were partly of chemical but chiefly of mechan- 
ical origin. Last of all came the Alluvial series. 

The existence of voleanoes had been pointed out long 
before Werner’s time by the Italian school of geologists, 
but as for ‘‘the universality and potency of what is now 
termed igneous action,’’ all was ‘‘brushed aside by the 
oracle of Freiberg.’’ Reactions between the interior 
and exterior of our earth ‘‘were utterly antagonistic to 
Werner’s conception of the structure and history of the 
earth.’’ To him, volcanoes were ‘‘burning mountains’’ 
that arose from the combustion of subterranean beds of 
coal, spontaneously ignited. 

The breaking down of the Wernerian doctrines began 
with two of Werner’s most distinguished pupils, D’Au- 
buisson de Voisins (1769-1819) and Von Buch. The 
former in 1803 had accepted Werner’s aqueous origin of 
basalt, but after studying the celebrated and quite recent 
volcanic area of Auvergne he recanted in 1804. Here he 
saw the basaltic rocks lying upon and cutting through 
granite, and in places more than 1200 feet thick. ‘‘If 
these basaltic rocks were lavas,’’ says Geikie, ‘‘they 
must, according to the Wernerian doctrine, have resulted 
from the combustion of beds of coal. But how could coal 
be supposed to exist under granite, which was the first 
chemical precipitate of a primeval ocean?’’ 

Leopold von Buch (1774-1853), ‘‘the most illustrious 


Charles Schuchert—Historical Geology, 1818-1918. 49 


geologist that Germany has produced,’’ after two years 
spent in Norway was satisfied ‘‘that the rocks in the 
Christiania district could not be arranged according to 
the Wernerian plan, which there completely broke down. 
Von Buch found a mass of granite lying among 
fossiliferous limestones which were manifestly meta- 
morphosed, and were pierced by veins of granite, por- 
phyry, and syenite.’’? Even so, he was not ready to 
abandon the teachings of his master. After a study 
of the mountain systems of Germany, however, ‘‘he | 
declared that the more elevated mountains had never 
been covered by the sea, as Werner had taught, but were 
produced by successive ruptures and uplifts of the ter- 
restrial crust’’ (Geikie). 

Rise of Geology and Conformism.—Modern geology 
has its rise in James Hutton (1726-1797) of Edinburgh, 
Scotland. In 1785 and 1795, Hutton published his 
Theory of the Earth, with Proofs and Illustrations. His 
‘“immortal theory’’ is his only work on geology. ‘‘For- 
tunately for Hutton’s fame and for the onward march of 
geology, the philosopher numbered among his friends the 
illustrious mathematician and natural philosopher, John 
Playfair (1748-1819), who had been closely associated 
with him in his later years, and was intimately con- 
versant with his geological opinions.’’ In 1802, Play- 
fair published his Ilustrations of the Huttonian Theory 
of the Earth, of which Geikie says, ‘‘Of this great classic 
it is impossible to speak too highly,’’ as it is at the basis 
of all modern geology. 

One of Hutton’s fundamental doctrines is that the 
earth is internally hot and that in the past large masses 
of molten material, the granites, have been intruded into 
the crust. It was these igneous views that led to his 
followers being called the Plutonists. Another of his 
ereat doctrines was that ‘‘the ruins of an earlier world 
lie beneath the secondary strata,’’ and that they are sep- 
arated by what is now known as unconformity. He 
clearly recognized a lost interval in the broken relation 
of the structures, and that the ruins, the detrital mate- 
rials, of one world after another are superposed in the 
structure of the earth. 

Hutton also held that the deformation of once horizon- 
tally deposited strata was probably brought about at dif- 
ferent periods by great convulsions that shook the very 


50 Charles Schuchert—Historical Geology, 1818-1918. 


foundations of the earth. After a convulsion, there was 
a long time of erosion, represented by the unconformity. 
Geikie says, ‘‘The whole of the modern doctrine of 
earth sculpture is to be found in the Huttonian theory.’’ 
The Lyellian doctrine of metamorphism had its origin 
in Hutton, for he showed that invading igneous granite 
had altered, through its heat and expanding power, the 
originally water-laid sediments, and that the schists of 
the Alps had been born of the sea like other strati- 
fied rocks. | 
Hutton is the father of the Uniformitarian principle, 
for he ‘‘started with the grand conception that the past 
history of our globe must be explained by what can be 
seen to be happening now, or to have happened only 
recently. The dominant idea in his philosophy is that 
the present is the key to the past.’’ This principle has 
been impressed on all later geologists by Sir Charles 
Lyell, and is the chief cornerstone of modern geology. 
The principle of uniformitarianism has underlain 
geologic interpretation since the days of Hutton, Play- 
fair, and Lyell. However, it is often applied too rigidly 
in interpretations based upon the present conditions, 
because in the past there were long times when the topo- 
eraphic features of the earth were very different from 
those of to-day. Throughout the Paleozoic, and, less 
markedly, the Mesozoic, the oceans flooded the lands 
widely (at times over 60 per cent of the total area), high- 
lands were inconspicuous, sediments far scarcer, and cli- 
mates warm and equable throughout the world. High- 
land conditions, and especially the broadly emergent con- 
tinents of the present, were only periodically present in 
the Paleozoic and then for comparatively short intervals 
between the periods. Therefore rates of denudation, 
solution, sedimentation, and evolution have varied 
greatly throughout the geological ages. These differ- 
ences, however, relate to degrees of operation, and not to 
kinds of processes; but the differences in degree of 
operation react mightily on our views as to the age of 
the earth. | 
Geologic time had, for Hutton, no ‘‘vestige of a begin- 
ning, no prospect of an end.’’ In other words, geologic 
time is infinite. He did not, however, discover a method 
by which the chronology of the earth could be determined. 
First Important Teat-books.—In 1822 appeared the 


Charles Schuchert—Historical Geology, 1818-1918. 51 


ablest text-book so far published, and the pattern for 
most of the later ones, Outlines of the Geology of Eng- 
land and Wales, by W. D. Conybeare (1787-1857) and W. 
Phillips (1775-1828). ‘‘In this excellent volume all that 
was then known regarding the rocks of the country, from 
the youngest formations down to the Old Red Sandstone, 
was summarized in so clear and methodical a manner as 
to give a powerful impulse to the cultivation of geology 
in Kngland’’ (Geikie). This book is reviewed at great 
length by Edward Hitchcock in the Journal (7, 203, 1824). 

To indicate how far historical geology had progressed 
up to 1822 in England, a digest of the geological column 
as presented in this text-book is given in the following 
table, along with other information. 

A text-book writer of yet greater influence was Charles 
Lyell (1797-1875), whose Principles of Geology appeared 
in three volumes between 1830 and 1833. This and his 
other books were kept up to date through many editions, 
and his Elements of Geology is, as Geikie says, ‘‘the hand 
book of every English geologist’’ working with the fos- 
siliferous formations. 


THE RiIsE oF GEoLocy IN NortH AMERICA. 


The generating Centers.—In America, geology had its 
rise independently in three places: in the two scientific 
societies of Boston and Philadelphia, and dominantly in 
Benjamin Silliman of Yale College. Stated in another 
way, we may say that geology in America had its origin 
in the following pioneers and founders: first, in William 
Maclure at Philadelphia, and next in Benjamin Silliman 
at New Haven. Through the influence of the latter, 
Amos Eaton, the botanist, became a geologist and taught 
geology at Williams College and later at the Rensselaer 
School in Troy, New York. Through the same infiuence 
Rev. Edward Hitchcock also became a geologist and 
taught the subject after 1825 at Amherst College. 

Silliman was the first to take up actively the teach- 
ing of mineralogy and geology based on collections of 
specimens. He spread the knowledge in popular lectures 
throughout the Eastern States, graduated many a stu- 
dent in the sciences, making of some of them professional 
teachers and geologists, provided all with a journal 
wherein they could publish their research, organized the 
first geological society and through his students the first 


THE GEOLOGICAL COLUMN IN 1822 


| 
Wer- | Other 


Present American as C.&P. : , 
: Conybeare and Phillips 1822 nerian| writ- 
classification orders| orders! ers 
Psychozoic or Recent | Alluvial nm 
ray es] 
o = WM 
ro oO Es 
Pleistocene Diluvial 5 = © 
ba : ; S) 
aoc cae, Upper Marine formation (Crag,| § = a 
S Feces? Neogene Bagshot sand, and Isle of Wight)| “5 fs = 
= Freshwater formations = 2 5 
© | Oligocene London Clay sD 2 a 
Eocene | Paleogene Plastic Clay ; A 
| Cretaceous Chalk 
| Beds between Chalk and Oolite 
Comanchian 1887 Series (Chalk Marle, Green Sand, 
| Weald Clay, Iron Sand) 
( Upper Oolitic division (Purbeck| 5% as 
S | beds, Portland Oolite, Kimmer-| mn D 
e idge Clay) S 2 & 
Ss Middle Oolitic division (Coral Rag, = S Oo 
Sg | Oxford Clay) = iS) Ds 
ei | Jurassic 1829 4 | Lower Oolitic division (Cornbrash,| © N 3 
| Stonesfield Slate, Forest Marble, : = i 
Great Oolite, Fullers’ Earth, In-| & fy iS 
ferior Oolite, Sand and Marle-| # oe 
stone 
| | Lias 
Triassic 1834 New Red Sandstone 
ro} ;o 
| Permian 1841 Magnesian Limestone = 3 
pie Eaaacideera dO Re 24 = 
Coal Measures Sis 
2 | Pennsylvanian 1891 eS x 
2 | Mississippian 1869 | Millstone Grit and Shale S2un| S 
S Old Red Sandstone S& 5| -3 oS 
= | Devonian 1839 5 @ = 
™ | Silurian 1835 S @ 
Ordovician 1879 H = 
(=Lower Silurian 1835) 5a 
Cambrian 1833 Unresolved 
2 as : 
Q | Keweenawan) « Submedial © © 
oy) sucinaowlathay vet aN ie a! 
al = \- fo) oo) om 
S | Huronian { & ss = Ss 
(oe) 1 1 om om 
& Sudburian J] an and i a 
PRR 1 oD j 
} i g 19 , 
&.2 | Keewatin | @ ‘Inferior Orders: - 
2 & | Coutchiching { 3 ¢ ; 
<q Hes 


Charles Schuchert—Historical Geology, 1818-1918. 53 


official geological surveys, and by kind words and acts 
stimulated, fostered, and held together American scien- 
tific men for fifty years. Of him it has been truly said 
that he was ‘‘the guardian of American science from its 
childhood.’’ 

The American Academy in Boston.—The second oldest 
scientific society, but the first one to publish on geological 
subjects, was the American Academy of Arts and 
Sciences of Boston, instituted and publishing since 1780. 
Up to the time of the founding of this Journal, there had 
appeared in the publications of the American Academy 
about a dozen papers of a geologic character, none of 
which need to be mentioned here excepting one by S. L. 
and J. F. Dana, entitled ‘‘Outlines of the Mineralogy and 
Geology of Boston,’’ published in 1818. This is an early 
and important step in the elucidation of one of the most 
intricate geologic areas, and is further noteworthy for its 
geologic map, the third one to appear, the older ones 
being by Maclure and Hitcheock (Merrill). 

Early Geology m Philadelphia.—The oldest scientific 
society is the American Philosophical Society of Phila- 
- delphia, started by the many-sided Benjamin Franklin in 
1769, and which has published since 1771. Up to the time 
of the founding of the Journal in 1818, there had 
appeared in the publications of this society thirteen 
papers of a geologic nature, nearly all small building 
stones in the rising geologic story of North America. 
The only fundamental ones were Maclure’s Observations 
of 1809 and 1817. Later, in this same city, there was 
organized another scientific society that came to be for 
a long time the most active one in America. This was 
the Academy of Natural Sciences, started in 1812 with 
seven members, but it was not until 1817 and the election 
of William Maclure as its first president that the work 
of the Academy was of a far-reaching character. Here 
was built up not only a society for the advancement of the 
natural sciences and publications for the dissemination 
of such knowledge, but, what is equally important, the 
first large library and general museum. 

William Maclure (1763-1840), correctly named by Sil- 
liman the ‘‘father of American geology,’’ was born and 
educated in Scotland, and died near Mexico City. A 
merchant of London until 1796, when he had already 
amassed ‘‘a considerable fortune,’’ he made a first short 


a De aXx——EOEeEeEE—E—eEEeE—EeEeE————————————————————— ee 


54 Charles Schuchert—Historical Geology, 1818-1918. 


visit to New York City in 1782. In 1796 he again came 
to America, this time to become a citizen of this country 
and a liberal patron of science. 

About 1803, single-handed and unsustained by gov- 
ernment patronage, Maclure interested himself most 
zealously and efficiently in American geology. In 1809 
he published his Observations on the Geology of the 
United States, Explanatory of a Geological Map. This 
work he revised ‘‘on a yet more extended seale,’’ issuing 
it in 1817 with 130 pages of text, accompanied by a large 
colored geological map. 

Silluman, the pioneer Promoter of Geology.—In 1806 
when Benjamin Silliman (1779-1864) began actively to 
teach chemistry and mineralogy, all the sciences in Amer- 
1¢ca Were in a very backward state, and the earth sciences 
were not recognized as such in the curricula of any of our 
colleges. Silliman gave his first lecture in chemistry on 
April 4, 1804. In the summer of that year, Yale College 
asked him to go to England to purchase material for the 
College, and great possibilities for broadening his 
knowledge now loomed before him. As Silliman himself 
(43, 225, 1842) has told the interesting story of his 
sojourn in England and Scotland, it is worth while to 
restate a part of it here. 

‘‘Passing over to England in the spring of 1805, and fixing 
my residence for six months in London, I found there no school, 
public or private, for geological instruction, and no association 
for the cultivation of the science, which was not even named in 
the English universities.’’ In geology ‘‘Edinburgh was then 
far in advance of London . . . Prof. Jameson having recently 
returned from the school of Werner, fully instructed in the doc- 
trines of his illustrious teacher, was ardently engaged to maintain 
them, and his eloquent and acute friend, the late Dr. John Mur- 
ray, was a powerful auxiliary in the same cause; both of these 
philosophers strenuously maintaining the ascendancy of the 
aqueous over the igneous agencies, in the geological phenomena 
_ of our planet. 

On the other hand, the disciples and friends of Dr. Hutton 
were not less active. He died in 1797, and his mantle fell upon 
Sir James Hall, who, with Prof. Playfair and Prof. Thomas 
Hope, maintained with signal ability, the igneous theory of 
Hutton. It did not become one who was still a youth and a 
novice, to enter the arena of the geological tournament where 
such powerful champions waged war; but it was very interest- 
ing to view the combat, well sustained as it was on both sides, 
and protracted, without a decisive issue, into a drawn battle. . . 


Charles Schuchert—Historical Geology, 1818-1918. 55 


The conflicts of the rival schools of Edinburgh—the Neptun- 
ists and the Vulcanists, the Wernerians and the Huttonians, 
were sustained with great zeal, energy, talent, and science; they 
were indeed marked too decidedly by a partisan spirit, but this 
very spirit excited untiring activity in discovering, arranging, 
and criticising the facts of geology. It was a transition period 
between the epoch of geological hypotheses and dreams, which 
had passed by, and the era of strict philosophical induction, in 
which the geologists of the present day are trained . ; 

I was a diligent and delighted listener to the discussions of 
both schools. Still the igneous philosophers appeared to me to 
assume more than had been proved regarding internal heat. 
In imagination we were plunged into a fiery Phlegethon, and I 
was glad to find relief in the cold bath of the Wernerian ocean, 
where my predilections inclined me to linger.’’ 


Silluman’s Students and their Publications.—Silli- 
man’s first student to take up geology as a profession was 
Denison Olmstead (1791-1859), educator, chemist, and 
geologist, who was graduated from Yale in 1813. Four 
years later he was under special preparation with Silli- 
man in mineralogy and geology, and in that year was 
appointed professor of chemistry in the University of 
North Carolina. In 1824-1825 Olmstead issued a Report 
on the Geology of North Carolina, which is the first off- 
cial geological report issued by any state in America, 
‘fa conspicuous and solitary imstance,’’ according to 
Hitcheock’s review of it (14, 2380, 1828), ‘‘in which any 
of our state governments have undertaken thoroughly to 
develop their mineral resources.’’ 

Amos Eaton (1776-1842), lawyer, botanist, surveyor, 
and one of the founders of American eeology, was a 
graduate of Williams College in the class of 1799. He 
studied with Silliman in 1815, attending his lectures on 
chemistry, geology, and mineralogy. He also enjoyed 
access to the libraries of Silliman and of the bot- 
anist, Levi Ives, in which works on botany and materia 
medica were prominent, and was a diligent student of the 
College cabinet of minerals. He settled as a lawyer and 
land agent in Catskill, New York, and here in 1810 he 
gave a popular course of lectures on botany, believed to 
have been the first attempted in the United States. 

In 1818 appeared Eaton’s first noteworthy geological 
publication, the Index to the Geology of the Northern 
States, a text-book for the classes in geology at Williams- 
town. The controlling principle of this book was Wer- 


96 Charles Schuchert—Mistorical Geology, 1818-1918. 


nerism, a false doctrine from which Haton was never 
able to free himself. This book was ‘‘written over 
anew’’ and published in 1820. 

While at Albany in 1818, Governor De Witt Clinton 
asked Eaton to deliver a course of lectures on chemistry 
and geology before the members of the legislature of 
New York. It is believed that Eaton is the only Ameri- 
can having this distinction, and because of it he became 
acquainted with many leading men of the state, inter- 
esting them in geology and its application to agriculture 
by means of surveys. In this way was sown the idea 
which eventually was to fructify in that great official 
work: The Natural History of New York. (See 43, 215, 
1842; and Youmans’ sketch of Haton’s life, Pop. Sci. 
Monthly, Nov. 1890.) 

Edward Hitcheock (1793-1864), reverend, state geolo- 
gist, college president, and another of the founders of 
American geology, was largely self-taught. Previous to 
1825, when he entered the theological department of Yale 
College, he had met Amos Eaton, who interested him 
in botany and mineralogy, and between 1815 and 1819 
he had made lists of the plants and minerals found about 
his native town, Deerfield, Massachusetts. Therefore, 
while studying theology at Yale it was natural for him 
also to take up mineralogy and geology with Silliman, 
whose acquaintance he had made at least as early as 1818. 

Hitcheoek, who was destined to be one of the most 
prominent figures of his time, was appointed in 1825 to 
the chair of chemistry and natural history at Amherst 
College. His first geologic paper, one of five pages, 
appeared in 1815. Three years later appeared his more 
important paper on the Geology and Mineralogy of a 
Section of Massachusetts, New Hampshire, and Vermont 
(1, 105, 436, 1818). This is also noteworthy for its 
geological map, the next one to be published after those 
of Maclure of 1809 and 1817, In 1823 came a still 
oreater work, A Sketch of the Geology, Mineralogy, and 
Scenery of the Regions contiguous to the River Connecti- 
cut (6, 1, 200, 1823; 7, 1, 1824). Here the map above 
referred to was greatly improved, and the survey was 
one of the most important of the older publications. : 

Youmans in his account of Hitchcock (Pop. Sei. 
Monthly, Sept. 1895) says: | | 


Charles Schuchert—Historical Geology, 1818-1918. 57% 


‘‘The State of Massachusetts commissioned him to make a 
geological survey of her territory in 1830. Three years were 
spent in the explorations, and the work was of such a high char- 
acter that other States were induced to follow the example of 
Massachusetts . . . The State of New York sought his advice 
in the organization of a survey, and followed his suggestions, 
particularly in the division of the territory into four parts, and 
appointed him as the geologist of the first district. He entered 
upon the work, but after a few days of labor he found that he 
must necessarily be separated from his family, much to his dis- 
inclination. He also conceived the idea of urging a more thor- 
ough survey of his own State; hence he resigned his commission 
and returned home. The effort for a resurvey of Massachusetts 
was successful, and he was recommissioned to do the work. The 
results appeared in 1841 and 1844.”’ 


Oliver P. Hubbard was assistant to Silliman in 1831- 
1836, and then up to 1866 taught chemistry, mineralogy, 
and geology at Dartmouth College. James G. Percival 
was graduated at Yale in 1815, and in 1835 he and C. U. 
Shepard of Amherst College were appointed state geol- 
ogists of Connecticut. Their report was issued in 1842. 

James Dwight Dana (1813-1895) was undoubtedly the 
ablest of all of Silliman’s students. Graduated at Yale 
in 1833, he spent fifteen months in the United States 
Navy as instructor in mathematics, cruising off France, 
Italy, Greece, and Turkey. In 1836 he was assistant to 
Silliman, and in 1837, at the age of twenty-four years, 
he published his widely used System of Mineralogy. 
Two years later Dana joined the Wilkes Exploring Expe- 
dition as mineralogist, returning to America in 1842; his 
geological results of this expedition were published in 
1849. In 1863, during the Rebellion, he published his 
Manual of Geology, and through four editions it 
remained for forty years the standard text-book for 
American geologists. 

First American Geological Society—The founding in 
1807 of the Geological Society of London, the parent of 
geological societies, undoubtedly had its stimulating 
effect on Silliman, and with his marked organizing ability 
he began to think of forming an American society of the 
same kind. This he brought about the year following 
the appearance of this Journal. that is, in 1819. The 
American Geological Society, begun in 1819 (1, 442, 
1819), was terminated in 1830 (17, 202, 1830). The first 


58 Charles Schuchert—Historical Geology, 1818-1918. 


meeting (September 6, 1819) and all the subsequent ones 
were held in the cabinet of Yale College. The brief 
records of the doings of this society are printed in vol- 
umes 1, 10, 15, and 18 of the Journal. Silliman was the 
attraction at the meetings, surrounded by his mineral. 
cabinet, and he gave ‘‘the true scientific dress to all the 
naked mineralogical subjects’’ discussed. 


WERNERIAN GEOLOGY IN NortH AMERICA. 


The Father of American Geology.—Historical Geology 
begins in America with William Maclure’s Observations 
on the Geology of the United States, issued in 1809. 
This was the first important original work on North 
American geology, and its colored geological map was the 
first one of the area east of the Mississippi River. The 
classification was essentially the Wernerian system. All 
of the strata of the Coastal Plain, now known to range 
from the Lower Cretaceous to Recent, were referred to 
the Alluvial. To the west, over the area of the Piedmont, 
were his Primitive rocks, while the older Paleozoic 
formations of the Appalachian ranges were referred to 
the Transition. West of the folded area, all was Floetz 
or Secondary, or what we now know as Paleozoic sedi- 
mentaries. The Triassic of the Piedmont area and that 
of Connecticut he called the Old Red Sandstone, and the 
coal formations of the interior region he said rested upon 
the Secondary. The second edition of the work in 1817 
was much improved, along with the map, which was also 
printed on a more correct geographic base. (Kor greater 
detail, see Merrill, Contributions to the History of 
American Geology, 1906.) 

Even though Maclure’s geologic maps are much gen- 
eralized, and the scheme of classification adopted a very 
broad one, they are in the main correct, even if they do 
emphasize unduly the rather simple geologic structure 
of North America. This fact is patent all through 
Maclure’s description. Cleaveland also refers to it in 
his treatise of 1816, and Silliman in the opening volume 
of the Journal (1, 7, 1818) says: ‘‘The outlines of Amer- 
can geology appear to be particularly grand, simple, and 
instructive.’’ Then, all the kinds of rocks were compre- 
hended under four classes, Primitive, Transition, Allu- 
vial, and Volcanic. It is also interesting to note here 
that in 1822 Maclure had lost faith in the aqueous origin 


Charles Schuchert—Historical Geology, 1818-1918. 59 


of the igneous rocks and writes of the Wernerian system 
as ‘‘fast going out of fashion’’ (5, 197, 1822), while 
Hitchcock said about the same thing in 1825 (9, 146). 


The Work of Eaton—Amos Eaton, after traveling — 


10,000 miles and completing his Hrie Canal Report in 
1824, ‘‘reviewed the whole line several times,’’ and pub- 
hshed in 1828 in the Journal (14, 145) a paper on Geolog- 
ical Nomenclature, Classes of Rocks, ete. The broader 
classification is the Wernerian one of Primitive, Transi- 
tion, and Secondary classes. Under the first two he has 
fossiliferous early Paleozoic formations, but does not 
know it, because he pays no attention anywhere to the 
detail of the entombed fossils, and all of his Secondary 
is what we now call Paleozoic. The correlations of the 
latter are faulty throughout. 

Then came his paper of 1830, Geological Prodromus 
(17, 63), im which he says: ‘‘I intend to demonstrate 
... that all geological strata are arranged in five analo- 
gous series; and that each series consists of three forma- 
tions; viz., the Carboniferous [meaning mud-stones], 
Quartzose, and Calcareous.’’ We seem to see here 
expressed for the first time the idea of ‘‘cycles of sedi- 
mentation,’’ but Haton does not emphasize this idea, and 
the localities given for each ‘‘formation’’ of ‘‘analogous 
series’’ demonstrate beyond a doubt that he did not have 
a sedimentary sequence. The whole is simply a jumble 
of unrelated formations that happen to agree more or 
less in their physical characters. 

‘‘T intend to demonstrate,’’ he says further, ‘‘that 
the detritus of New Jersey, embracing the marle, which 
contains those remarkable fossil relics, is antediluvial, or 
the genuine Tertiary formation.’’ This correlation had 
been clearly shown by Finch in 1824 (7, 31) and yet both 
are in error in that they do not distinguish the included 
Cretaceous marls and greensands as something apart 
from the Tertiary. 

One gets impatient with the later writings of Eaton, 
because he does not become liberalized with the progres- 
sive ideas in stratigraphic geology developing first in 
Kurope and then in America, especially among the geolo- 
gists of Philadelphia. Therefore it is not profitable to 
follow his work further. 

Early American Teat-books of Geoloqgy.—The first 
American text-book of geology bears the date of Boston 


60 Charles Schuchert—Historical Geology, 1818-1918. 


1816 and is entitled An Elementary Treatise on Mineral- 
ogy and Geology, its author being Parker Cleaveland of 
Bowdoin College. The second edition appeared in 1822. 
It also had a geologic map of the United States, practi- 
cally a copy of Maclure’s. To mineralogy were devoted 
085 pages, and to geology 55, of which 37 describe rocks 
and 5 the geology of the United States. The chronology 
is Wernerian. Of ‘‘geological systems’’ there are two, 
‘‘primitive and secondary rocks.’’ 

In 1818 appeared Amos Eaton’s Index to the Geology 
of the Northern States, having 54 pages, and in 1820 
came the second edition, ‘‘wholly written over anew,’’ 
with 286 pages. The theory of the later edition is still 
that of Werner, with ‘‘improvements of Cuvier and 
Bakewell,’’? and yet one sees nowadays but little in it of 
the far better English text-book. Eaton did very little 
to advance philosophic geology in America. What 
is of most value here are his personal observations in 
regard to the local geology of western Massachusetts, 
Connecticut, southwestern Vermont, and eastern New 
York (1, 69, 1819; also Merrill, p. 234). 

We come now to the most comprehensive and advanced 
of the early text-books used in America. This is the 
third English edition of Robert Bakewell’s Introduction 
to Geology (400 pages, 1829), and the first American edi- 
tion ‘‘with an Appendix Containing an Outline of his 
Course of Lectures on Geology at Yale College, by Ben- 
jamin Silliman’’ (128 pages). Bakewell’s good book is 
in keeping with the time, and while not so advanced as 
Conybeare and Phillips’s Outlines of 1822, yet is far 
more so than Silliman’s appendix. The latter is general 
and not specific as to details; it is still decidedly Wer- 
nerian, though in a modified form. Silliman says he is 
‘‘neither Wernerian nor Huttonian,’’ and yet his sum- 
mary on pages 120 to 126 shows clearly that he was not 
only a Wernerian but a pietist as well. : 


UNEARTHING OF THE CENOZOIC AND Mesozoic IN NortH AMERICA. 


The Discerning of the Tertiary—The New England 
States, with their essentially igneous and metamorphic 
formations, could not furnish the proper geologic envi- 
ronment for the development of stratigraphers and 
paleontologists. So in America we see the rise of such 
geologists first in Philadelphia, where they had easy 


Charles Schuchert—Historical Geology, 1818-1918. 61 


access to the horizontal and highly fossiliferous strata of 
the coastal plain. The first one to attract attention was 
Thomas Say, after him came John Finch, followed by 
Lardner Vanuxem, Isaac Lea, Samuel G. Morton, and 
T. A. Conrad. These men not only worked out the 
succession of the Cenozoic and the upper part of the 


Mesozoic, but blazed the way among the Paleozoic strata 


as well. 

Thomas Say (1787-1834), in 1819, was the first Ameri- 
ean to point out the chronogenetic value of fossils in his 
article, Observations on some Species of Zoophytes, 
Shells, ete., principally Fossil (1, 381). He correctly 
states that the progress of geology ‘‘must be in part 
founded on a knowledge of the different genera and 
species of reliquiz, which the various accessible strata of 
the earth present.’’ Say fully realizes the difficulties in 
the study of fossils, because of their fragmental charac- 
ter and changed nature, and that their correct interpre- 
tation requires a knowledge of similar living organisms. 

The application of what Say pointed out came first in 
John Finch’s Geological Essay on the Tertiary Forma- 
tions in America (7, 31, 1824). Even though the paper 
is still laboring under the mineral system and does not 
discern the presence of Cretaceous strata among his Ter- 
tiary formations, yet Finch also sees that ‘‘fossils con- 
stitute the medals of the ancient world, by which to ascer- 
tain the various periods.’’ 

Finch now objects to the wide misuse in America of 
the term alluvial and holds that it is applied to what is 
elsewhere known as Tertiary. He says: 

‘*Geology will achieve a triumph in America, when the term 
alluvial shall be banished from her Geological Essays, or con- 
fined to its legitimate domain, and then her tertiary formations 
will be seen to coincide with those of Europe, and the formations 
of London, Paris, and the Isle of Wight, will find kindred asso- 
ciations in Virginia, the Carolinas, Georgias, the Floridas, and 
Louisiana.’’ 


The formations as he has them from the bottom 
upwards are: (1) Ferruginous sand, (2) Plastic clay, 
(3) Caleaire Silicieuse of the Paris Basin, (4) London 
Clay, (5) Caleaire Ostrée, (6) Upper marine formation, 
(7) Diluvial. 

The grandest of these early stratigraphic papers, 
however, is that by Lardner Vanuxem (1792-1848), of 


62 Charles Schuchert—Historical Geology, 1818-1918. 


only three pages, entitled ‘‘Remarks on the Characters 
and Classification of Certain American Rock Forma- 
tions’’ (16, 254, 1829). Vanuxem, a cautious man anda. 
profound thinker, had been educated at the Paris School 
of Mines. James Hall told the writer in a conversation 
that while the first New York State Survey was in oper- 
ation, all of its members looked to Vanuxem for advice. 

In the paper above referred to, Vanuxem points out in 
a very concise manner that: 


‘‘The alluvial of Mr. Maclure . . . contains not only well 
characterized alluvion, but products of the tertiary and second- 
ary classes. Littoral shells, similar to those of the English and 
Paris basins, and pelagic shells, similar to those of the chalk 
deposition or latest secondary, abound in it. These two kinds 
of shells are not mixed with each other; they occur in different 
earthy matter, and, in the southern states particularly, are at 
different levels. The incoherency or earthiness of the mass, and 
our former ignorance of the true position of the shells, have been 
the sources of our erroneous views.’’ 


The second error of the older geologists, according to 
Vanuxem, was the extension of the secondary rocks over 
‘‘the western country, and the back and upper parts of 
New York.’’ They are now called Paleozoic. Some had 
even tried to show the presence of Jurassic here because 
of the existence of oolite strata. ‘‘It was taken for 
granted, that all horizontal rocks are secondary, and as 
the rocks of these parts of the United States are horizon- 
tal in their position, so they were supposed to be second- 
ary.’’ He then shows on the basis of similar Ordovician 
fossils that the rocks of Trenton Falls, New York, recur 
at Frankfort in Kentucky, and at Nashville in Tennessee. 

‘Tt is also certain that an uplifting or downfalling 
force, or both, have existed, but it is not certain that 
either or both these forces have acted in a uniform man- 
ner. ... Innumerable are the facts, which have fallen 
under my observation, which show the fallacy of adopt- 
ing inclination for the character of a class,’’ such as the 
Transition class of strata. He then goes on to say that 
in the interior of our country the so-called secondary 
rocks are horizontal and in the mountains to the east the 
same strata are highly inclined. ‘‘The analogy, or iden- 
tity of rocks, I determine by their fossils in the first 
instance, and their position and mineralogical characters 
in the second or last instance.’’ 


Charles Schuchert—Historical Geology, 1818-1918. 63 


It appears that Isaac Lea (1792-1886) in his Contri- 
-butions to Geology, 1833, was the first to transplant to 
America Lyell’s terms, Pliocene, Miocene, and Eocene, 
proposed the previous year. The celebrated Claiborne 
locality was made known to Lea in 1829, and in the work 
here cited he describes from it 250 species, of which 200 
are new. The horizon is correlated with the London 
Clay and with the Caleaire Grossier of France, both of 
Kocene time (25, 413, 1834). 

Timothy A. Conrad began to write about the Ameri- 
can Tertiary in 1830, and his more important publica- 
tions were issued at Philadelphia. His papers in the 
Journal begin with 1833 and the last one on the Tertiary 
is in 1846. 

The Tertiary faunas and stratigraphy have been 
modernized by William H. Dall in his monumental work 
of 1650 pages and 60 plates entitled ‘‘Contributions to 
the Tertiary Fauna of Florida’’ (1885-1903). Here more 
than 3160 forms of the Atlantic and Gulf deposits are 
described, but in order to understand their relations to 
the fossil faunas elsewhere and to the living world, the 
author studied over 10,000 species. Since then, many 
other workers have interested themselves in the Tertiary 
problems. Much good work is also being done in 
the Pacific States where the sequence is being rapidly 
developed. 

The Discerning of the Eastern Cretaceous.—The Cre- 
taceous sequence was first determined by that ‘‘active 
and acute geologist,’’ Samuel G. Morton (1799-1851), but 
that these rocks might be present along the Atlantic 
border had been surmised as early as 1824 by Edward 
Hiteheock (7, 216). Vanuxem, as above pointed out, 
indicated the presence of the Cretaceous in 1829. In 
this same year Morton proved its presence before the 
Philadelphia Academy of Natural Sciences. 

Between 1830 and 1835 Morton published a series of 
papers in the Journal under the title ‘‘Synopsis of the 
Organic Remains of the Ferruginous Sand Formation of 
the United States, with Geological Remarks’’ (17, 274, et 
seq.). In these he describes the Cretaceous fossils and 
demonstrates that the ‘‘ Diluvial’’ and Tertiary strata of 
the Atlantic border also have a long sequence of Creta- 
ceous formations. In the opening paper he writes: ‘‘I 
consider the marl of New Jersey as referable to the great 


64 Charles Schuchert—Historical Geology, 1818-1918. 


ferruginous sand series, which in Prof. Buckland’s 
arrangement is designated by the name of green sand. 
. .. On the continent this series is called the ancient 
chalk .. . lower chalk,’’ ete. Again, the marls of New 
Jersey are ‘‘geologically equivalent to those beds which 
in Europe are interposed between the white chalk and 
the QOolites.’’ This correlation is with the European 
Lower Cretaceous, but we now know the marls to be of 
Upper Cretaceous age. Although Eaton objected stren- 
uously to Morton’s correlation, we find M. Dufresnoy of 
France saying, ‘‘Your limestone above green sand 
reminds me very much of the Mestricht beds,’’ a correla- 
tion which stands to this day (22, 94, 1832). In 1833 Mor- 
ton announces that the Cretaceous is known all along the 
Atlantic and Gulf border, and in the Mississippi valley. 
‘‘The same species of fossils are found throughout,’’ and 
none of them are known in the Tertiary. He now 
arranges the strata of the former ‘‘ Alluvial’’ as follows: 


Alluvial. 
Modern Diluvial. 


Upper Tertiary (Upper Marine). 
Tertiary Middle Tertiary (London Clay). 
| Lower Tertiary (Plastic Clay). 
{ Caleareous Strata | Cretaceous group, or Ferrugi- 
Secondary | Ferruginous Sand § nous Sand series (24, 128). 


Western Cretaceous.—In 1841 and 1843 J. N. Nicollet 
announced the discovery of Cretaceous in the Rocky 
Mountain area. Of 20 species of fossils collected by 
him, 4 were said to occur on the Atlantic border, and of 
the 200 forms of the Atlantic slope only 1 was found in 
Hurope. Here we see pointed out a specific dissimilarity 
between the continents, and a similarity between the 
American areas of Cretaceous deposits (41, 181; 45, 153). 

The Cretaceous of the Rocky Mountains was clearly 
developed by F. V. Hayden in 1855-1888 and by F. B. 
Meek (1857-1876). Other workers in this field were 
Charles A. White (1869-1891), and R. P. Whitfield (1877- 
1889). Since 1891 T. W. Stanton has been actively inter- 
preting its stratigraphy and faunas. 

Cretaceous and Comanche of Texas.—The broader 
outlines of the Cretaceous of Texas had been described 
by Ferdinand Roemer in 1852 in his good work, Kreide- 


Charles Schuchert—Historical Geology, 1818-1918. 65 


bildungen von Texas, but it was not until 1887 that 
Robert T. Hill showed in the Journal (33, 291) that it 
included two great series, the Gulf series, or what we now 
call Upper Cretaceous, and a new one, the Comanche 
series. This was a very important step in the right 
direction. Since then the Comanche series has been 
regarded by some stratigraphers as of period value, 
while others call it Lower Cretaceous; the rest of the 
Texas Cretaceous is divided by Hill into Middle and 
Upper Cretaceous. On the other hand, Lower Creta- 
ceous strata had been proved even earlier in the state of 
California, for here in 1869 W. M. Gabb (1839-1878) and 
J. D. Whitney (1819-1896) had defined their Shasta 
group, which was wholly distinct faunally from the 
Comanche of Texas and the southern part of the Great 
Plains country. | 

Jurassic and Triassic of the West.—In 1864, the Geo- 
logical Survey of California proved the presence of 
marine Upper Triassic in that State, and since then it 
has been shown that not only is all of the Triassic present 
in Idaho (where it has been known since 1877), Oregon, 
Nevada, and California, but that the Upper Triassic is 
of very wide distribution throughout western North 
America. Jurassic strata, on the other hand, were not 
shown to be present in California until 1885, while in the 
Rocky Mountain area of the United States there was 
long known an unresolved series of ‘‘Red Beds’’ sit- 
uated between the Carboniferous and Cretaceous. This 
gave rise to the ‘‘Red Bed problem,’’ the history of 
which is given by ©. A. White in the Journal (17, 214, 
1879). In 1869, F. V. Hayden announced the discovery 
of marine Jurassic fossils in this series, and since then 
they have come to be known as the Sundance fauna, 
extending from southern Utah and Colorado into Alaska. 
Above lie the dinosaur-bearing fresh-water deposits, 
since 1894 known as the Morrison beds. In 1896, O. C. 
Marsh (1831-1899) announced the presence of Jurassic 
fresh-water ‘strata along the Atlantic coast (2, 433), but 
to-day only a small part of them are regarded as of the 
age of the Morrison, while the far greater part are 
referred to the Comanche or Lower Cretaceous. The 
red beds below the Jurassic of the Rocky Mountain area 
have during the past twenty years been shown to be in 
part of Upper Triassic age and of fresh-water origin, 


Am. Jour. Sct.—FourtH SERIES, VoL. XLVI, No. 271.—Jutty, 1918. 
3 


66 Charles Schuchert—Historical Geology, 1818-1918. 


while the greater lower part 1s connected with the Car- 
boniferous series and is made up of brackish- and fresh- 
water deposits of probable Permian time. 

Triassic of Atlantic States—The fresh-water Triassic 
of the Atlantic border states was first mentioned by 
Maclure (1817), who regarded it as the equivalent of the 
Old Red Sandstone of Europe. In this he was followed 
by Hitchcock in 1823 (6, 39), the latter saying that above 
it lies ‘‘the coal formation,’’ which is true for EKurope, 
but in America the coal strata are older than these red 
beds, now known to be of Triassic age. 

The first one to question this correlation was Alex- 
andre Brongniart, who had received from Hitchcock rock 
specimens and a fossil fish which he erroneously identi- 
fied with a Permian species, and accordingly referred 
the strata to the Permian (3, 220, 1821; 6, 76, pl. 9, figs. 1, 
2, 1823). The discerning Professor Finch in 1826 
remarked that the red beds of Connecticut appear to 
belong ‘‘to the new or variegated sandstone,’’ because of 
eight different criteria that he mentions. Of these, but 
two are of value in correlation, their ‘‘geological posi- 
tion’’ and the presence of bones other than fishes. In 
the Connecticut area, however, the geological position 
cannot be determined even to-day, and in Finch’s time 
the bones of dinosaurs were unknown. Finch then goes 
on to point out the occurrences of Old Red Sandstone in 
Pennsylvania, but all of the places he refers to are either 
younger or older in time. Here we again see the fatality 
of trying to make positive correlations on the basis of 
lithology and color (10, 209, 1826). In 1835, however, 
Hitchcock showed that the bones that had been found in 
1820 were those of a saurian, and accordingly referred 
the strata of the Connecticut valley to the New Red 
Sandstone, a term that then covered both the Permian 
and the Triassic. In 1842, W. B. Rogers referred the 
beds to the Jurassic, on the basis of plants from Virginia. 
In 1856, W. C. Redfield (1789-1857), because of the fishes, 
advocated a Lias, or Jurassic age, and proposed the 
name Newark group for all the Triassic deposits of the 
Atlantic border. More recently, on the basis of the 
plants studied by Newberry, Fontaine, Sturr, and Ward, 
and the vertebrates described by Marsh and Lull, the 
age has been definitely fixed as Upper Triassic (see 
Dana’s Manual of Geology, 740, 1895). er ae 


Charles Schuchert—Historical Geology, 1818-1918. 67 


UNEARTHING OF THE PALEOZOIC IN NortH AMERICA. 


Permian of the United States——In Europe, previous to 
1841, the formations now classed as Permian were 
included in the New Red Sandstone, and with the Car- 
boniferous were referred to the Secondary. In that 
year Murchison proposed the period term Permian. In 
1845 came the classic Geology of Russia in Europe and 
the Ural Mountains, by Murchison, Keyserling, and De 
Verneuil. In this great work the authors separated out 
of the New Red the Magnesian Limestone of Great Brit- 
ain and the Rothliegende marls, Kupferschiefer, and 
Zechstein of Germany, and with other formations of the 
Urals in Russia, referred them to the Permian system. 
This step, one of the most discerning in historical geol- 
ogy, was all the more important because they closed the 
Paleozoic era with the Permian, beginning the Second- 
ary, or Mesozoic, with the New Red Sandstone or the 
Triassic period. There is a good review of this work by 
D. D. Owen (1807-1860) in the Journal for 1847 (3, 153). 

Owen, though accepting the Permian system, is not 
‘satisfied with its reference to the Paleozoic, and he sets 
the matter forth in the Journal (38, 365, 1847). He 
doubts ‘‘the propriety of a classification which throws 
the Permian and Carboniferous systems into the Paleo- 
zoic period.’’ This is mainly because there is no ‘‘evi- 
dence of disturbance or unconformability’’ between the 
Permian and Triassic systems. Rather ‘‘there is so 
complete a blending of adjacent strata’’ that it is only 
in Russia that the Permian has been distinguished from 
the Triassic. This view of Owen’s was not only correct 
for Russia but even more so for the Alps and for India, 
and it has taken a great deal of work and discussion to 
fix upon the disconformable contact that distinguishes 
the Paleozoic from the Mesozoic in these areas. In 
other words, there was here at this time no mountain 
making. Then Owen goes on to state that because the 
Permian of Europe has reptiles, he sees in them decisive 
Mesozoic evidence. ‘‘These are certainly strong argu- 
ments in favor of placing, not only the Permian, but also 
the Carboniferous group in the Mesozoic period, and ter- 
minating the Paleozoic division with the commencement 
of the coal measures.’’ To this harking backward the 


68 Charles Schuchert—Historical Geology, 1818-1918. 


geologists of the world have not agreed, but have fol- 
lowed the better views of Murchison and his associates. 

In 1855 G. G. Shumard discovered, and in 1860 his 
brother B. F. Shumard (1820-1869) announced, the 
presence of Permian strata in the Guadalupe Mountains 
of Texas, and in 1902 George H. Girty (14, 363) con- 
firmed this. Guirty regards the faunas as younger than 
any other late Paleozoic ones of America, and says: 
‘‘Hor this reason I propose to give them a regional name, 
which shall be employed in a force similar to Mississip- 
pian and Pennsylvanian. ... The term Guadalupian is 
suggested. ”’ 

G. C. Swallow (1817-1899) in 1858 was the first to 
announce the presence of Permian fossils in Kansas, and 
this led to a controversy between himself and EF’. B. Meek, 
both claiming the discovery. It is only in more recent 
years that it has been generally admitted that there is 
Permian in that state, in Oklahoma, and in Texas. This 
admission came. the more readily through the discovery 
of many reptiles in the red beds of Texas, and through 
the work of C. A. White, published in 1891, The Texan 
Permian and its Mesozoic Types of Fossils (Bull. U. S. 
Geological Survey, No. 77). 

Carbonferous Formations.—The coal formations are 
noted in a general way throughout the earliest volumes 
of the Journal. The first accounts of the presence of 
coal, in Ohio, are by Caleb Atwater (1, 227, 239, 1819), 
and 8S. P. Hildreth (13, 38, 40, 1828). The first coal 
plants to be described and illustrated were also from 
Ohio, in an article by Ebenezer Granger in 1821 (3, 5-7). 
The anthracite field was first described in 1822 by Zach- 
ariah Cist (4, 1) and then by Benjamin Silliman (10, 
331-351, 1826); that of western Pennsylvania was 
described by William Meade in 1828 (13, 32). 

The Lower Carboniferous was first recognized by W. 
W. Mather in 1838 (34, 356). Later, through the work 
of Alexander Winchell (1824-1891), beginning in 1862 
(33, 352) and continuing until 1871, and through the 
surveys of Iowa (1855-1858), Illinois (essentially the 
work of A. H. Worthen, 1858-1888), Ohio (1838, Mather, 
etc.), and Indiana (Owen, etc., 1838), there was even- 
tually worked out the following succession: 


Charles Schuchert—Historical Geology, 1818-1918. 69 


Permian period. 
Upper Barren series. 
Dunkard group. 
Washington group. 
Pennsylvanian period. 
Upper Productive Coal series. Monongahela series. 
Lower Barren Coal Measures. Conemaugh series. 
Lower Productive Coal Measures. Allegheny series. 
Pottsville series. 


The New York System.—We now come to the epochal 
survey of the State of New York, one that established 
the principles of, and put order into, American strati- 
eraphy from the Upper Cambrian to the top of the 
Devonian. No better area could have been selected for 
the establishing of this sequence. This survey also 
developed a stratigraphic nomenclature based on New 
York localities and rock exposures, and made full use of 
the entombed fossils in correlation. Incidentally it devel- 
oped and brought into prominence James Hall, who con- 
tinued the stratigraphic work so well begun and who 
also laid the foundation for paleontology in America, 
becoming its leading invertebrate worker. 

This work is reviewed at great length in the Journal 
in the volumes for 1844-1847 by D. D. Owen. Evidently 
it followed too new a plan to receive fulsome praise from 
conservative Owen, as it should have. He remarks that 
the volumes ‘‘are not a little prolix, are voluminous and 
expensive, and do not give as clear and connected a view 
of the geological features of the state as could be wished. 
... We are of the opinion that before this work can 
become generally useful and extensively circulated, it 
must be condensed and arranged into one compendious 
volume’’ (46, 144, 1844). This was never done and yet 
the work was everywhere accepted at once, and to this 
end undoubtedly Owen’s detailed review helped much. 

The Natural History Survey of New York was organ- 
ized in 1836 and completed in 1843. The state was 
divided into four districts, and to these were finally 
assigned the following experienced geologists. The 
southeastern part was named the First District, with W. 
W. Mather (1804-1859) as geologist; the northeastern 
quarter was the Second District, with Ebenezer Emmons 
(1799-1863) in charge; the central portion was the Third 
District, under Lardner Vanuxem (1792-1848); while 


70 Charles Schuchert—Historical Geology, 1818-1918. 


the western part was James Hall’s (1811-1898) Fourth 
District. Paleontology for a time was in charge of T. A. 
Conrad (1830-1877), the mineralogical and chemical work 
was in the hands of Lewis C. Beck; the botanist was 
John Torrey; and the zoologist James DeKay. 

The New York State Survey published six annual 
reports of 1675 pages octavo, and four final geological 
reports with 2079 pages quarto. Finally in 1846 
Hmmons added another volume on the soils and rocks 
of the state, in which he also discussed the Taconic and 
New York systems; it has 371 pages. With the com- 
pletion of the first survey, Hall took up his life work 
under the auspices of the state—his monumental work, 
Paleontology of New York, in fifteen quarto volumes of 
4539 pages and 1081 plates of fossils. In addition to all 
this, there are his annual and other reports to the 
Regents of the State, so that it is safe to say that he 
published not less than 10,000 pages of printed matter 
on the geology and paleontology of North America. 

In regard to this great series of works, all that can be 
presented here is a table of formations as developed by 
the New York State Survey. Practically all of its 
results and formation names have come into general use, 
with the exception of the Taconic system of Emmons and 
the division terms of the New York system. (See p. 71.) 

The New York State Survey, begun in 1836, was con- 
tinued by James Hall from 1843 to 1898. During this 
time he was also state geologist of Iowa (1855-1858) and 
Michigan (1862). Since 1898, John M. Clarke has ably 
continued the Geological Survey of New York, the state 
which continues to be, in science and more especially in 
geology and paleontology, the foremost in America. 

Western Extension of the New York system.—Before 
Hall finished his final report, we find him in 1841 on ‘“‘a 
tour of exploration through the states of Ohio, Indiana, 
Illinois, a part of Michigan, Kentucky, and Missouri, and 
the territories of Jowa and Wisconsin.’’ This tour is 
described in the Journal (42, 51, 1842) under the caption 
‘Notes upon the Geology of the Western States.’’ His 
object was to ascertain how far the New York system as 
the standard of reference ‘‘was applicable in the western 
extension of the series.’’ In a general way he was very 
successful in extending the system to the Mississippi 
River, and he clearly saw ‘‘a great diminution, first of 


Charles Schuchert—Historical Geology, 1818-1918. 71 


The Geological Column of the New York Geologists of 1842-1843, 
according to W. W. Mather 1842. 


Alluvial division. 
Quaternary system Quaternary division. 
Drift division. 


. These strata are included in the next 

Tertiary system He 
lower division. 

Long Island division. Equals the Ter- 

tiary and Cretaceous marls, sands, 

and clays of the coastal plain of New 


Upper Secondary Jersey. 
system Trappean division. New Beducrstem 
The Palisades of Emmons and 
Red Sandstone Pitfall 


division. 

Coal system of Mather, and Carboniferous system of Hall. 
Old Red system of Catskill Mountains of Emmons; Catskill 
division of Mather and Hall; and Catskill group of Vanuxem. 


According to Hall 1843, and essentially Vanuxem 1842. 


Chemung, Portage or Nunda (divided 
into Cashaqua, Gardeau, Portage), 
Genesee, Tully, Hamilton (divided 
into Ludlowville, Encrinal, Moscow), 
and Marcellus. 


Goet Onondaga, Schoharie, Cau- 


Erie division 
[| Devonian | 


Helderberg series 
| Devonian- 
Silurian | 


da-gali, Oriskany, Upper Pentame- 

rus, Enerinal, Delthyris, Pentamerus, 

| Waterlime, Onondaga salt group. 

Ontario division 
[ Silurian | 


Champlain division | Oneida or Shawangunk, Grey sandstone, 


Niagara, Clinton, and Medina. 


ase: 3 Hudson River group, Utica, Trenton, 
[Silurian-Ordovi- Black River including Birdseye and 


cian-Upper é 
eee Chazy, Calciferous sandrock, and 
Potsdam. 
According to Emmons 1842, Mather 1843, Vanuxem 1842, 
: Hall 1843. 


ARS aoa Magnesian slate, and Taconic slate. 


Primary or Hypo- 


Taconic system | Granular quartz, Stockbridge limestone, 
] 
gene system 


Metamorphic and Primary rocks. 


72 Charles Schuchert—HMistorical Geology, 1818-1918. 


sandy matter, and next of shale, as we go westward, and 
in the whole, a great increase of caleareous matter in the 
same direction.’’ He also clearly noted the warped 
nature of the strata, the ‘‘anticlinal axis,’’ since known 
as the Cincinnati and Wabash uplifts and the Ozark 
dome. 

Hall, however, fell into a number of flagrant errors 
because of a too great reliance on lthologic correlation 
and supposedly similar sequence. For instance, the 
Coal Measures of Pennsylvania were said to directly 
overlap the Chemung group of southern New York, and 
now he finds the same condition in Ohio, Indiana, and 
Illinois, failing to see that in most places between the 
top of the New York system and the Coal Measures lay 
the extensive Mississippian series, one that he generally 
confounded with the Chemung, or included in the ‘‘Car- 
boniferous group.’’ He states that the Portage of New 
York is the same as the Waverly of Ohio, and at Louis- 
ville the Middle Devonian waterlime is. correlated with 
the similar rock of the New York Silurian. Hall was 
especially desirous of fixing the horizon of the Middle 
Ordovician lead-bearing rocks of Illinois, Wisconsin, and 
Towa, but unfortunately correlated them with the Niag- 
aran, while the Middle Devonian about Columbus, Ohio, 
and Louisville, Kentucky, he referred to the same 
horizon. The Galena-Niagaran error was corrected in 
1855, but the Devonian and Mississippian ones remained 
unadjusted for a long time, and in Iowa until toward the 
close of the nineteenth century. 

Correlations with Europe—The first effort toward 
correlating the New York system with those of Kurope 
was made by Conrad in his Notes on American Geology 
in 1839 (35, 243). Here he compares it on faunal 
grounds with the Silurian system. A more sustained 
effort was that of Hall in 1843 (45, 157), when he said 
that the Silurian of Murchison was equal to the New 
York system and embraced the Cambrian, Silurian, and 
Devonian, which he considered as forming but one sys- 
tem. Hall in 1844 and Conrad earlier were erroneously 
regarding the Middle Devonian of New York (Hamilton) 
as ‘‘an equivalent of the Ludlow rocks of Mr. Murcehi- 
son’’ (47, 118, 1844). 

In 1846 KE. P. De Verneuil spent the summer in Amer- 
ica with a view to correlating the formations of the New 


Charles Schuchert—Historical Geology, 1818-1918. 73 


York system with those of Europe. At this time he had 
had a wide field experience in France, Germany, and 
Russia, was president of the Geological Society of 
France, and ‘‘virtually the representative of Kuropean 
geology’’ (2, 153, 1846). Hall says, ‘‘No other person 
could have presented so clear and perfect a coup d’oeil.’’ 
De Verneuil’s results were translated by Hall and with 
his own comments were published in the Journal in 1848 
and 1849 under the title ‘‘On the Parallelism of the 
Paleozoic Deposits of North America with those of 
EKurope.’’ De Verneuil was especially struck with the 
complete development of American Paleozoic deposits 
and said it was the best anywhere. On the other hand, 
he did not agree with the detailed arrangement of the 
formations in the various divisions of the New York 
system, and Hall admitted altogether too readily that the 
terms were proposed ‘‘as a matter of concession, and it is 
to be regretted that such an artificial classification was 
adopted.’’ De Verneuil’s correlations are as follows: 

The Lower Silurian system begins with the Potsdam, 
the analogue of the Obolus sandstone of Russia and 
Sweden. The Black River and Trenton hold the position 
of the Orthoceras limestones of Sweden and Russia, 
while the Utica and Lorraine are represented by the 
Graptolite beds of the same countries. Both correlations 
are in partial error. He unites the Chazy, Birdseye, and 
Black River in one series, and in another the Trenton, 
Utica, and Lorraine. Of species common to Kurope and 
America he makes out seventeen. 

In the Upper Silurian system, the Oneida and 
Shawangunk are taken out of the Champlain division, 
and, with the Medina, are referred to the Silurian, along 
with all of the Ontario division plus the Lower Helder- 
berg. The Clinton is regarded as highest Caradoc or as 
holding a stage between that and the Wenlock. The 
Niagara group is held to be the exact equivalent of the 
Wenlock, ‘‘ahile the five inferior groups of the Helder- 
berg division represent the rocks of Ludlow.’’ We now 
know that these Helderberg formations are Lower Devo- 
mian in age. De Verneuil unites in one series the 
Waterlime, Pentamerus, Delthyris, Encrinal, and Upper 
Pentamerus. Of identical species there are forty com- 
mon to Europe and America. 

The Devonian system De Verneuil begins, ‘‘after 


74 Charles Schuchert—HMistorical Geology, 1818-1918. 


much hesitation,’’ with the Oriskany and certainly with 
the five upper members of Hall’s Helderberg division, all 
of the Erie and the Old Red Sandstone. He also adjusts 
Hall’s error by placing in the Devonian the Upper Cliff 
hmestone of Ohio and Indiana, regarded by the former 
as Silurian. The Oriskany is correlated with the grau- 
wackes of the Rhine, and the Onondaga or Corniferous 
with the lower HEifelian. Cauda-galli, Schoharie, and 
Onondaga are united in one series; Marcellus, Hamilton, 
Tully, and Genesee in another; and Portage and 
Chemung in a third. Of species common to Europe and 
America there are thirty-nine. 

The Waverly of Ohio and that near Louisville, Ken- 
tucky, which Hall had called Chemung, De Verneuil cor- 
rectly refers to the Carboniferous, but to this Hall does 
not consent. De Verneuil points out that there are 
thirty-one species in common between HKurope and Amer- 
ica. ‘‘And as to plants, the immense quantity of terres- 
trial species identical on the two sides of the Atlantic, 
proves that the coal was formed in the neighborhood of 
lands already emerged, and placed in similar physical 
conditions. ’’ 

An analysis of the Paleozoic fossils of HKurope and 
America leads De Verneuil to ‘‘the conviction that identi- 
cal species have lived at the same epoch in America and 
in Kurope, that they have had nearly the same duration, 
and that they succeeded each other in the same order.’’ 
This he states is independent of the depth of the seas, 
and of ‘‘the upheavings which have affected the surface 
of the globe.’’ The species of a period begin and drop 
out at different levels, and toward the top of a system 
the whole takes on the character of the next one. ‘‘If it 
happens that in the two countries a certain number of 
systems, characterized by the same fossils, are superim- 
posed in the same order, whatever may be, otherwise, 
their thickness and the number of physical groups of 
which they are composed, it is philosophical to consider 
these systems as parallel and synchronous.”’ 


Because of the dominance of the sandstones and shales 


in eastern New York,.De Verneuil holds that a land lay 
to the east. The many fucoids and ripple-marks from 
the Potsdam to the Portage indicated to him shallow 
water and nearness to a shore. 


rm ee | eee ee eee 


Charles Schuchert—Historical Geology, 1818-1918. 75 


The Oldest Geologic Eras.—We have seen in previous 
pages how the Primitive rocks of Arduino and of Werner 
had been resolved, at least in part, into the systems of 
the Paleozoic, but there still remained many areas of 
ancient rocks that could not be adjusted into the accepted 
scheme. One of the most extensive of these is in Canada, 
where the really Primitive formations, of granites, 
eneisses, schists, and even undetermined sediments, 
abound and are developed on a grander scale than else- 
where, covering more than two million square miles and 
overlain unconformably by the Paleozoic and later rocks. 
The first to call attention to them was J. I. Bigsby, a 
medical staff officer of the British Army, in 1821 (8, 
254). It was, however, William E. Logan (1798-1875), 
the ‘‘father of Canadian geology,’’ who first unravelled 
their historical sequence. At first he also called them 
Primary, but after much work he perceived in them par- 
allel structures and metamorphosed sediments, under- 
lain by and associated with pink granites. For the 
oldest masses, essentially the granites, he proposed the 
term Laurentian system (1853, 1863) and for the altered 
and deformed strata,.the name Huronian series (1857, 
1863). Overlying these unconformably was a third 
series, the copper-bearing rocks. Since his day a great 
host of Canadian and American geologists have labored 
over this, the most intricate of all geology, and now we 
have the following tentative chronology (Schuchert and 
Barrell, 38, 1, 1914): 


Late Proterozoic era. 

Keweenawan, Animikian and Huronian periods. 
Karly Proterozoic era. 

Sudburian period or older Huronian. 
Archeozoie era. 

Grenville series, ete. 
Cosmic history. 


THe Taconic System RESURRECTED. 


The -Taconic system was first announced by Ebenezer 
Emmons in 1841, and clearly defined in 1842. It started 
the most bitter and most protracted discussion in the 
annals of American geology. After Emmons’s subse- 
quent publications had put the Taconic system through 
three phases, Barrande of Bohemia in 1860-1863 shed a 
great deal of new and correct light upon it, affirming ina 


76 Charles Schuchert—Mstorical Geology, 1818-1918. 


series of letters to Billings that the Taconic fossils are 
like those of his Primordial system, or what we now eall 
the Middle Cambrian (31, 210, 1861, et seq.). 

In a series of articles published by S. W. Ford in the 
Journal between 1871 and 1886, there was developed the 
further new fact that in Rensselaer and Columbia coun- 
ties, New York, the so-called Hudson River group 
abounds in ‘‘Primordial’’ fossils wholly unlike those of 
the Potsdam, and which Ford later on spoke of as 
belonging to ‘‘Lower Potsdam”’ time. 

James D. Dana entered the field of the Taconic area in 
1871 and demonstrated that the system also abounds in 
Ordovician fossiliferous formations. Then came the 
far-reaching work of Charles D. Walcott, beginning in 
1886, which showed that all through eastern New York 
and into northern Vermont the Hudson River group and 
the Taconic system abound not only in Ordovician but 
also in Cambrian fossils. Finally in 1888 Dana pre- 
sented a Brief History of Taconic Ideas, and laid away 
the system with these words (36, 27) : 


‘‘Tt is almost fifty years since the Taconic system made its 
abrupt entrance into geological science. Notwithstanding some 
good points, it has been through its greater errors, long a hin- 
drance to progress here and abroad . . . But, whether the evil 
or the good has predominated, we may now hope, while heartily 
honoring Professor Emmons for his earnest geological labors and 
his discoveries, that Taconic ideas may be allowed to be and 
remain part of the past.’’ 


As an epitaph Dana placed over the remains of the 
Taconic system the black-faced numerals 1841-1888. 
That the remains of the system, however, and the term 
Taconic are still alive and demanding a rehearing is 
apparent to all interested stratigraphers. This is not 
the place to set the matter right, and all that can be done 
at the present time is to point out what are the things 
that still keep alive Emmons’s system. 

In the typical area of the Taconic system, 1. e., in Rens- 
selaer County, Emmons in 1844-1846 produced the fossils 
Atops triineatus and Elliptocephala asaphoides. 8S. W.. 
Ford, as stated above, later produced from the same gen- 
eral area many other fossils that he demonstrated to be 
older than the Potsdam sandstone. ‘'T'o this time he gave 
the name of Lower Potsdam, thus proving on paleon- 
tological grounds that at least some part of the Taconic 


Charles Schuchert—Historical Geology, 1818-1918. 77 


system is older than the New York system, and therefore 
older than the Hudson River group of Ordovician age. 

In 1888 Walcott presented his conclusions in regard to 
the sequence of the strata in the typical Taconic area and 
to the north and south of it. He collected Lower Cam- 
brian fossils at more than one hundred localities 
‘within the typical Taconic area,’’ and said that the 
thickness of his ‘‘terrane No. 5”’ or ‘‘Cambrian (Geor- 
gia),’’ now referable to the Lower Cambrian, is ‘‘14,000 
feet or more.’’ He demonstrated that the Lower Cam- 
brian is infolded with the Lower and Middle Ordovician, 
and confirmed Emmons’s statement that the former rests 
upon his Primary or Pre-Cambrian masses. Elsewhere, 
he writes: ‘‘To the west of the Taconic range the sec- 
tion passes down through the limestone (3) [of Lower 
and Middle Ordovician age] to the hydromiea schists (2) 
[whose age may also be of early Ordovician], and thence 
to the great development of slates and shales with their 
interbedded sparry limestones, calciferous and arenaceous 
strata, all of which contain more or less of the Olenellus 
... fauna.’’ He then knew thirty-five species in Wash- 
ington County, New York (35, 401, 1888). 

Finally in 1915 Walcott said that in the Cordilleran 
area of America there was a movement that brought 
about changes ‘‘in the sedimentation and succession of 
the faunas which serve to draw a boundary line between 


the Lower and Middle Cambrian series.... The 
length of this period of interruption must have been con- 
siderable . . . and when connection with the Pacific was 


resumed a new fauna that had been developing in the 
Pacific was then introduced into the Cordilleran sea and 
constituted the Middle Cambrian fauna. The change 
in the species from the Lower to the Middle Cambrian 
fauna is very great.’’ He thén goes on to show that in 
the Appalachian geosyncline there was another move- 
ment that shut out the Middle Cambrian Paradoxides 
fauna of the Atlantic realm from this trough, and all 
deposition as well. 

Conclusions.—Accordingly it appears that everywhere 
in America the Lower Cambrian formations are sep- 
arated by a land interval of long duration from those of 
Middle Cambrian time. These formations therefore 
unite into a natural system of rocks or a period of time. 
Between Middle and Upper Cambrian time, however, 


78 Charles Schuchert—Historical Geology, 1818-1918. | 


there appears to be a complete transition in the Cordil- 
leran trough, binding these two series of deposits into 
one natural or diastrophic system. Hence the writer 
proposes that the Lower Cambrian of America be known 
as the Taconic system. The Middle and Upper Cam- 
brian series can be continued for the present under the 
term Cambrian system, a term, however, that is by no 
means in good standing for these formations, as will be 
demonstrated under the discussion of the Silurian con- 
troversy. 


THE SILURIAN CONTROVERSY. 


Just as in America the base of the Paleozoic was 
involved in a protracted controversy, so in England the 
Cambrian-Silurian succession was a subject of long 
debate between Sedgwick and Murchison, and among the 
succeeding geologists of Hurope. The history of the 
solution is so well and justly stated in the Journal by 
James D. Dana under the title ‘‘Sedgwick and Murchi- 
son: Cambrian and Silurian’’ (39, 167, 1890), and by Sir 
Archibald Geikie in his Text-book of Geology, 1903, that 
all that is here required is to briefly restate it and to 
bring the solution up to date. 

Adam Sedgwick (1785-1873) and R. I. Murchison 
(1792-1871) each began to work in the areas of Cam- 
bria (Wales) and Siluria (England) in 1831, but the 
terms Cambrian and Silurian were not published until 
1835. Murchison was the first to satisfactorily work out 
the sequence of the Silurian system because of the 
simpler structural and more fossiliferous condition of 
his area. Sedgwick, on the other hand, had his academic 
duties to perform at Cambridge University, and being an 
older and more conservative man, delayed publishing his 
final results, because of the further fact that his area 
was far more deformed and less fossiliferous. In 1834 
they were working in concert in the Silurian area, and 
Sedgewick said: ‘‘I was so struck by the clearness of the 
natural sections and the perfection of his workmanship 
that I received, I might say, with implicit faith every- — 
thing which he then taught me. . . . The whole ‘Silurian 
system’ was by its author placed above the great undu- 
lating slate-rocks of South Wales.’’ At that time Mur- 
ehison told Sedgwick that the Bala group of the latter, 
now known to be in the middle of the Lower Silurian, 


Charles Schuchert—Historical Geology, 1818-1918. ‘9 


could not be brought within the limits of the Silurian 
system, and added, ‘‘I believe it to plunge under the true 
Llandeilo-flags,’?’ now placed next below the Bala and 
above the Arenig, which at the present is regarded as at 
the base of the Ordovician. 

The Silurian system was defined in print by Murchison 
in July, 1835, the Upper Silurian embracing the Ludlow 
* and Wenlock, while the Lower Silurian was based on the 
Caradoc and Llandeilo. Murchison’s monumental work, 
The Silurian System, of 100 pages and many plates of 
fossils, appeared in 1838. 

The Cambrian system was described for the first time 
by Sedgewick in August, 1835, but the completed work—a 
classic in geology—Synopsis of the Classification of the 
British Paleozoic Rocks, along with M’Coy’s Descriptions 
of British Paleozoic Fossils, did not appear until 1852- 
1855. Sedgwick’s original Upper Cambrian included the 
greater part of the chain of the Berwyns, where he said 
it was connected with the Llandeilo flags of the Silurian. 
The Middle Cambrian comprised the higher mountains of 
Cernarvonshire and Merionethshire, and the Lower 
Cambrian was said to occupy the southwest coast of 
Cernarvonshire, and to consist of chlorite and mica 
schists, and some serpentine and granular limestone. In 
1853 it was seen that the fossiliferous Upper Cambrian 
included the Arenig, Llandeilo, Bala, Caradoc, Coniston, 
Hirnant, and Lower Llandovery. On the other hand, it 
was not until long after Murchison and Sedgwick passed 
away that the Middle and Lower Cambrian were shown 
to have fossils, but few of those that characterize what 
is now called Lower, Middle, and Upper Cambrian time. 

Not until long after the original announcement of the 
Cambrian system did Sedgwick become aware ‘‘of the 
unfortunate mischief-involving fact’’ that the most fos- 
siliferous portion of the Cambrian—the Upper Cambrian 
—and at that time the only part yielding determinable 
fossils, when compared with the Lower Silurian was 
seen to be an equivalent formation but with very dif- 
ferent lithologic conditions. He began to see in 1842 
that his Cambrian was in conflict with the Silurian sys- 
tem, and four years later there were serious divergencies 
of views between himself and Murchison. The climax 
of the controversy was attained in 1852, when Sedgwick 
was extending his Cambrian system upwards to include 


80 Charles Schuchert—Historical Geology, 1818-1918. 


the Bala, Llandeilo, and Caradoe, a proceeding not unlike 
that of Murchison, who earlier had been extending his 
Silurian downward through all of the fossiliferous Cam- 
brian to the base of the Lingula flags. 

Dana in his review of the Silurian-Cambrian contro- 
versy states: ‘‘The claim of a worker to affix a name to a 
series of rocks first studied and defined by him cannot be 
disputed.’’ We have seen that Murchison had priority 
of publication in his term Silurian over Sedgwick’s Cam- 
brian, but that in a complete presentation, both strati- . 
graphically and faunally, the former had years of prior 
definition. What has even more weight is that geologists 
nearly everywhere had accepted Murchison’s Silurian 
system as founded upon the Lower and Upper Silurian 
formations. A nomenclature once widely accepted is 
almost impossible to dislodge. However, in regard to 
the controversy it should not be forgotten that it. was 
only Murehison’s Lower Silurian that was in conflict 
with Sedgwick’s Upper Cambrian. As for the rest of 
the Cambrian, that was not involved in the controversy. 

Dana goes on to state that science may accept a name, 
or not, according as it is, or is not, needed. In the prog- 
ress of geology, he thought that the time had finally been 
reached when the name Cambrian was a necessity, and 
he ineluded both Cambrian and Silurian in the geologi- 
eal record. The ‘‘Silurian,’’ however, included the Lower 
and Upper Silurian—not one system of rocks, but two. 

It is now twenty-seven years since Dana came to this 
conclusion, at a time when it was believed that there was 
more or less continuous deposition not only between the 
formations of a system but between the systems them- 
selves as well. To-day many geologists hold that in the 
course of time the oceans pulsate back and forth over 
the continents, and accordingly that the sequence of 
marine sedimentation in most places must be much 
broken, and to-day we know that the breaks or land inter- 
vals in the marine record are most marked between the 
eras, and shorter between all or at least most of the 
periods. Furthermore, in North America, we have — 
learned that the breaks between the systems are most 
marked in the interior of the continent and less so on or 
toward its margins. 

Hardly any one now questions the fact of a long land 
interval between the Lower Silurian and Upper Silurian 


Charles Schuchert—HMistorical Geology, 1818-1918. 81 


in England, and it is to Sedgwick’s credit that he was the 
first to point out this fact and also the presence of an 
unconformity. It therefore follows that we cannot con- 
tinue to use Silurian system in the sense proposed by 
Murchison, since it includes two distinct systems or 
periods. Dana, in the last edition of his Manual of 
Geology (1895), also recognizes two systems, but 
curiously he saw nothing incongruous in ealling them 
- *fLower Silurian era’’ and ‘‘Upper Silurian era.’’ It 
certainly is not conducive to clear thinking, however, to 
refer to two systems by the one name of Silurian and to 
speak of them individually as Lower and Upper Silurian, 
thus giving the impression that the two systems are but 
parts of one—the Silurian. Each one of the parts has its 
independent faunal and physical characters. 

We must digress a little here and note the work of 
Joachim Barrande (1799-1883) in Bohemia. In 1846 he 
published a short account of the ‘‘Silurian system’’ of 
Bohemia, dividing it into étages lettered C to H. 
Between 1852 and 1883 he issued his ‘‘Systéme Silurien 
du Centre de la Bohéme,’’ in eighteen quarto volumes 
with 5568 pages of text and 798 plates of fossils—a mon- 
umental work unrivalled in paleontology. In the first 
volume the geology of Bohemia is set forth, and here we 
see that étages A and B are Azoic or pre-Cambrian, and 
C to H make up his Silurian system. Etage C has his 
‘“Primordial fauna,’’ now known to be of Paradoxides or 
Middle Cambrian time, while D is Lower Silurian, E is 
Upper Silurian, F is Lower Devonian, and G and H are 
Middle Devonian. From this it appears that Barrande’s » 
Silurian system is far more extensive than that of Murchi- 
son, embracing twice as many periods as that of England 
and Wales. 

About 1879 there was in England a nearly general 
agreement that Cambrian should embrace Barrande’s 
Primordial or Paradoxides faunas, and in the North 
Wales area be continued up to the top of the T’remadoce 
slates. -To-day we would include Middle and Upper 
Cambrian. Lower Cambrian in the sense of containing 
the Olenellus faunas was then unknown in Great Britain. 

Lapworth, recognizing the distinctness of the Lower 
Silurian as a system, proposed in 1879 to recognize it as 
such, and named it Ordovician, restricting Silurian to 
Murchison’s Upper Silurian. This term has not been 


82 Charles Schuchert—Historical Geology, 1818-1918. 


widely used either in Great Britain or on the Continent, 
but in the last twenty years has been accepted more and 
more widely in America. Even here, however, it is in 
direct conflict with the term Champlain, proposed by the 
New York State Geologist in 1842. 

In 1897 the International Geological Congress pub- 
lished IX. Renevier’s Chronographie Géeologique, wherein 
we find the following: 


Upper or Silurian Ludlowian (Murchison 1839). 
(Murchison, re- Wenlockian (Murchison 1839). 
stricted, 1835). Landoverian (Murehison). 

a Caradocian (Murchison 1839). 
wie Cee Tandeilian (Murchiens dean 
Pe ' ( Arenigian (Sedgwick 1847). 
Lower or Cambrian | stenevian (Emmons 1838). 


Silurian Period. 


(Sedgwick, re- Menevian (Salter and Hicks 1865). 
stricted, 1835). Georgian (Hitchcock 1861). 


Regarding this period, which, by the way, is not very 
unlike that of Barrande, Renevier remarks that it is ‘‘as 
important as the Cretaceous or the Jurassic. Lapworth — 
even gives it a value of the first order equal to the Pro- 
tozoic era.”’ 

In the above there is an obvious objection in the double 
usage of the term Silurian, and this difficulty was met 
later on in Lapparent’s Traité by the proposal to substi- 
tute Gothlandian for Silurian. Of this change Geikie 
remarks: ‘‘Such an arrangement ... might be adopted 
if it did not involve so serious an alteration of the nomen- 
clature in general use.’’ On the other hand, if dias- 
trophism and breaks in the stratigraphic and faunal 
sequence are to be the basis for geologic time divisions, 
we cannot accept the above scheme, for it recognizes 
but one period where there are at least four in nature. 

Conclusions.—We have arrived at a time when our 
knowledge of the stratigraphic and faunal sequence, plus 
the orogenic record as recognized in the principle of 
diastrophism, should be reflected in the terminology of 
the geologic time-table. It would be easy to offer a satis- 
factory nomenclature if we were not bound by the law of 
priority in publication, and if no one had the geologic 
chronology of his own time ingrained in his memory. 
In addition, the endless literature, with its accepted 
nomenclature, bars our way. Therefore with a view of 


Charles Schuchert—Historical Geology, 1818-1918. 88 


creating the least change in geologic nomenclature, and 
of doing the greatest justice to our predecessors that the 
present conditions of our knowledge will allow, the fol- 
lowing scheme is offered: 


Silurian period. Llandovery to top of Ludlow in Europe. 
Alexandrian-Cataract-Medina to top of Manlius in America. 

Champlain (1842) or Ordovician (1879) period. Arenig to top 
of Caradoc in Europe. Beekmantown to top of Richmondian 
in America. 

Cambrian period. In the Atlantic realm, begins with the 
Paradoxides, and in the Pacific, with the Bathyuriscus and 
Ogygopsis faunas. The close is involved in Ulrich’s provi- 
sionally defined Ozarkian system. When the latter is estab- 
lished, the Ozarkian period will hold the time between the 
Ordovician and the Cambrian. 

Taconic period. For the world-wide Olenellus or Mesonacide 
faunas. 


PALEOGEOGRAPHY. 


When geologists began to perceive the vast significance 
of Hutton’s. doctrine that ‘‘the ruins of an earlier world 
he beneath the secondary strata,’’ and that great masses 
of bedded rocks are separated from one another by 
periods of mountain making and by erosion intervals, it 
was natural for them to look for the lands that had fur- 
nished the débris of the accumulated sediments. In this 
way paleogeography had its origin, but it was at first of 
a descriptive and not of a cartographic nature. 

The word paleogeography was proposed by T. Sterry 
Hunt in 1872 in a paper entitled ‘‘The Paleogeography 
of the North American Continent,’’ and published in the 
Journal of the American Geographical Society for that 
year. It has to do, he says, with the ‘‘geographical his- 
tory of these ancient geological periods.’’ It was again 
prominently used by Robert Etheridge in his presidential 
address before the Geological Society of London in 1881. 
Since Canu’s use of the term in 1896, it has been fre- 
quently seen in print, and now is oenerally adopted to 
signify the geography of geologic time. 

The French were the first to make paleogeographic 
maps, and Jules Marcou relates in 1866 that Elie de 
Beaumont, as early as March, 1831, in his course in the 
College of France and at the Paris School of Mines, used 
to outline the relation of the lands and the seas in the 
center of Kurope at the different great geologic periods. 


84 Charles Schuchert—HMistorical Geology, 1818-1918. 


His first printed paleogeographic map appeared in 1833, 
and was of early Tertiary time. Other maps by Beau- 
mont were published by Beudant in 1841-1842. The 
Sicilian geologist Gemmellaro published six maps of his 
country in 1834, and the Englishman De La Beche had 
one in the same year. In America the first to show such 
maps was Arnold Guyot in his Lowell lectures of 1848. 
James D. Dana published three in the 1863 edition of his 
Manual of Geology. Of world paleogeographic maps, 
Jules Marcou produced the first of Jurassic time, pub- 
lishing it in France in 1866, but the most celebrated of 
these early attempts was the one by Neumayr published 
in 1883 in connection with his Ueber klimatische Zonen 
wahrend der Jura- und Kreidezeit. 

The first geologist to produce a series of maps showing 
the progressive geologic geography of a given area was 
Jukes-Brown, who in the volume entitled ‘‘The Building 
of the British Isles,’’ 1888, included fifteen such maps. 
Karpinsky published fourteen maps of Russia, and in 
1896 Canu in his Essai de paléogéographie has fifty-seven 
of France and Belgium. Lapparent’s Traité of 1906 is 
famous for paleogeographic maps, for he has twenty- 
three of the world, thirty-four of Europe, twenty-five of 
France, and ten taken from other authors. Schuchert in 
1910 published fifty-two to illustrate the paleogeography 
of North America, and also gave an extended list of such 
published maps. Another article on the subject is by Th. 
Arldt, ‘‘Zur Geschichte der Palaogeographischen Rekon- 
structionen,’’ published in 1914. Edgar Dacqué in 1913 
also produced a list in his Palaogeographischen Karten, 
and two years later appeared his book of 500 pages, 
Grundlagen und Methoden der Palaogeographie, where 
the entire subject is taken up in detail. 

Conclusions.—Sinee 1833 there have been published 
not less than 500 different paleogeographic maps, and of 
this number about 210 relate to North America. Never- 
theless paleogeography is still in its infaney, and most 
maps embrace too much geologic time, all of them tens 
of thousands, and some of them millions of years. The 
sveographic maps of the present show the conditions of 
the strand-lines of to-day, and those made fifty years ago 
have to be revised again and again if they are to be of 
value to the mariner and merchant. Therefore in our 
future paleogeographic maps the tendency must ever be 


Charles Schuchert—Historical Geology, 1818-1918. 85 


toward smaller amounts of geologic time, if we are to 
show the actual relation of water to land and the move- 
ments of the periodic floodings. Moreover, the ancient 
shore lines are all more or less hypothetic and are drawn 
in straight or sweeping curves, unlike modern strands 
with their bays, deltas, and headlands, and the ancient 
lands are featureless plains. We must also pay more 
attention to the distribution of brackish- and fresh-water 
deposits. The periodically rising mountains will be the 
first topographic features to be shown upon the ancient 
lands, and then more and more of the drainage and the 
general climatic conditions must be portrayed. In the 
seas, depth, temperature, and currents are yet to be 
deciphered. Finally, other base maps than those of the 
geography of to-day will have to be made, allowing for 
the compression of the mountainous areas, if we are to 
show the true geographic configurations of the lands and 
seas of any given geologic time. 


PALEOMETEOROLOGY. 


In accordance with the Laplacian theory, announced at 
the beginning of the nineteenth century, all of the older 
geologists held that the earth began as a hot star, and 
that in the course of time it slowly cooled and finally 
attained its present zonal cold to tropical climatic condi- 
tions. That the earth had very recently passed through 
a much colder climate, a glacial one, came into general 
acceptance only during the latter half of the previous 
century. 

Rise.—Our knowledge of glacial climates had its origin 
in the Alps, that wonderland of mountains and glaciers. 
The rise of this knowledge in the Alps is told in a charm- 
ing and detailed manner by that erratic French-Ameri- 
can geologist, Jules Marcou (1824-1898), in his Life, 
Letters, and Works of Louis Agassiz, 1896. He 
relates that the Alpine chamois hunter Perraudin in 1815 
directed the attention of the engineer De Charpentier to 
the fact-‘‘that the large boulders perched on the sides of 
the Alpine valleys were carried and left there by gla- 
ciers.’’? For a long time the latter thought the conclusion 
extravagant, and in the meantime Perraudin told the 
same thing to another engineer, Venetz. He, in 1829, 
convinced of the correctness of the chamois hunter’s 
views, presented the matter before the Swiss naturalists 


86 Charles Schuchert—Historical Geology, 1818-1918. 


then meeting at St. Bernard’s. Venetz ‘‘told the Society 
that his observations led him to believe that the whole 
Valais has been formerly covered by an immense glacier 
and that it even extended outside of the canton, covering 
all the Canton de Vaud, as far as the Jura Mountains, 
earrying the boulders and erratic materials, which are 
now scattered all over the large Swiss valley.’’? Hight 
years earlier, in 1821, similar views had been presented 
by the same modest naturalist before the Helvetic 
Society, but it was not until 1833 that De Charpentier 
found the manuscript and had it published. Venetz’s 
conclusions were that all of the glaciers of the Bagnes 
valley ‘‘have very recognizable moraines, which are 
about a league from the present ice.’’ ‘‘'The moraines 

date from an epoch which is lost in the night of 
ae > Then in 1834 De Charpentier read a paper 
before the same society, meeting at Lucerne. ‘‘Seldom, 
if ever, has such a small memoir so deeply excited the 
scientific world. It was received at first with incredulity 
and even scorn and mockery, Agassiz being among its 
opponents.’’ The paper was published in 1835, first at 
Paris, then at Geneva, and finally in Germany. It 
‘‘attracted much attention, and the smile of incredulity 
with which it was received when read at Lucerne soon 
changed into a desire to know more about it.’’ 

Louis Agassiz (1807-1873), who had long been ac- 
quainted with his countryman, De Charpentier, spent 
several months with him in 1836, and together they 
studied the glaciers of the Alps. Agassiz was at first 
‘fadverse to the hypothesis, and did not believe in the 
great extension of glaciers and their transportation of 
boulders, but on the contrary, was a partisan of Lyell’s 
theory of tr ansport by icebergs and ice-cakes .. . but 
from being an adversary of the glacial theory, he 
returned to Neuchatel an enthusiastic convert to the 
views of Venetz and De Charpentier. ... With his 
power of quick perception, his unmatched memory, his 
perspicacity and acuteness, his way of classifying, judg- 
ing and marshalling facts, Agassiz promptly learned the | 
whole mass of irresistible arguments collected patiently 
during seven years by De Charpentier and Venetz, and 
with his insatiable appetite and that faculty of assimila- 
tion which he possessed in such a wonderful degree, he 


Charles Schuchert—Historical Geology, 1818-1918. 87 


digested the whole doctrine of the glaciers in a few 
weeks. ”’ 

In July, 1837, Agassiz presented as his presidential! 
address before the Helvetic Society his memorable ‘‘ Dis- 
cours de Neuchatel,’’ which was ‘‘the starting point of 
all that has been written on the Ice-age,’’—a term coined 
at the time by his friend Schimper, a botanist. The first 
part of this address is reprinted in French in Marcou’s 
book on Agassiz. The address was received with aston- 
ishment, much incredulity, and indifference. Among the 
listeners was the great German geologist Von Buch, who 
‘‘was horrified, and with his hands raised towards the 
sky, and his head bowed to the distant Bernese Alps, 
exclaimed: ‘‘O Sancte de Saussure, ora pro nobis!’’ 
Even De Charpentier ‘‘was not gratified to see his glacial 
theory mixed with rather unealled for biological prob- 
Jems, the connection of which with the glacial age was 
more than problematic.’’ Agassiz was then a Cuvierian 
catastrophist and creationist, and advanced the idea of 
a series of glacial ages to explain the destruction of the 
geologic succession of faunas! Curiously, this theory 
was at once accepted by the American paleontologist 
T. A. Conrad (35, 239, 1839). 

The classics in glacial geology are Agassiz’s Etudes 
sur les Glaciers, 1840, and De Charpentier’s Essai sur les 
Glaciers, 1841. Of the latter book, Marcou states that 
it has been said: ‘‘It is impossible to be truly a geologist 
without having read and studied it.’’ In the English 
language there is T'yndall’s Glaciers of the Alps, 1860. 

The progress of the ideas in regard to Pleistocene 
glaciation is presented in the following chapter of this 
number by H. E. Gregory. 

Older Glacial Clinuites. —Hardly had the Pleistocene 
glacial climate been proved, when geologists began to 
point out the possibility of even earlier ones. An enthu- 
siastic Scotch writer, Sir Andrew Ramsay, in 1855 
described certain late Paleozoic conglomerates of middle 
England, which he said were of glacial origin, but his 
ev idence, though never completely ‘gainsaid, has not been 
venerally accepted. In the following year, an English- 
man, Doctor W. T. Blanford, said that the Talchir con- 
glomerates of central and southern India were of glacial 
origin, and since then the evidence for a Permian glacial 
climate has been steadily accumulating. Africa is the 


88 Charles Schuchert—HMistorical Geology, 1818-1918. 


land of tillites, and here in 1870 Sutherland pointed out 
that the conglomerates of the Karroo formation were of 
olacial origin. Australia also has Permian glacial 
deposits, and they are known widely in eastern Brazil, 
the Falkland Islands, the vicinity of Boston, and else- 
where. So convincing is this testimony that all geolo- 
gists are now ready to accept the conclusion that a 
glacial climate was as wide-spread in early Permian time 
as was that of the Pleistocene. | 

In South Africa, beneath the marine Lower Devonian, 
occurs the Table Mountain series, 5000 feet thick. The 
series 1s essentially one of quartzites, with zones of shales 
or slates and with striated pebbles up to 15 inches long. 
The latter occur in pockets and seem to be of glacial origin. 
There are here no typical tillites, and no striated under- 
grounds have so far been found. While the evidence of 
the deposits appears to favor the conclusion that the 
Table Mountain strata were laid down in cold waters with 
floating ice derived from glaciers, it is as yet impossible 
to assign these sediments a definite geologic age. They 
are certainly not younger than the Lower Devonian, but 
it has not yet been established to what period of the 
early Paleozoic they belong. 

In southeastern Australia occur tillites of wide distri- 
bution that he conformably beneath, but sharply sep- 
arated from the fossiliferous marine Lower Cambrian 
strata. _David (1907), Howchin (1908), and other Aus- 
tralian geologists think they are of Cambrian time, but 
to the writer they seem more probably late Proterozoic 
in age. In arctic Norway Reusch discovered unmistak- 
able tilliites in 1891, and this occurrence was confirmed by 
Strahan in 1897. It is not yet certainly known what 
their age is, but it appears to be late Proterozoic rather 
than early Paleozoic. Other undated Proterozoic tillites 
occur in China (Willis and Blackwelder 1907), Africa 
(Schwarz 1906), India (Vredenburg 1907), Canada 
(Coleman 1908), and possibly in Scotland. | 

The oldest known tillites are deseribed by Coleman in. 


1 For more detail in regard to these tillites and the older ones see Climates 
of Geologic Time, by Charles Schuchert, being Chapter XXI in Hunting- 
ton’s Climatic Factor as Illustrated in Arid America, Publication No. 
192 of the Carnegie Institution of Washington, 1914. Also Arthur P. 
Coleman’s presidential address before the Geological Society of America 
" toe Dry Land in Geology, published in the Society’s Bulletin, 27, 
divas LONG; “ 


Charles Schuchert—Historical Geology, 1818-1918. 89 


1907, and occur at the base of the Lower Huronian or in 
early Proterozoic time. They extend across northern 
Ontario for 1000 miles, and from the north shore of Lake 
Huron northward for 750 miles. 

Fossils as Climatic Indexes.—Paleontologists have 
long been aware that variations in the climates of the 
past are indicated by the fossils, and Neumayr in 1883 
brought the evidence together in his study of climatic 
zones mentioned elsewhere. Plants, and corals, cepha- 
lopods, and foraminifers among marine animals, have 
long been recognized as particularly good ‘‘life ther- 
mometers.’’ In fact, all fossils are climatic indicators 
to some extent, and a good deal of evidence concerning 
paleometeorology has been discerned in them. This evi- 
dence is briefly stated in the paper by Schuchert already 
alluded to, and in W. D. Matthew’s Climate and Evolu- 
tion, 1915. 

Sediments as Climatic Indexes.—Johannes Walther in 
the third part of his Einleitung—lLithogenesis der 
Gegenwart, 1894—is the first one to decidedly direct 
attention to the fact that the sediments also have within 
themselves a climatic record. In America Joseph Bar- 
rell has since 1907 written much on the same subject. 
On the other hand, the periodic floodings of the con- 
tinents by the oceans, and the making of mountains, 
due to the periodic shrinkage of the earth, as expressed 
in T. C. Chamberlin’s principle of diastrophism and in 
his publications since 1897, are other criteria for estimat- 
ing the climates of the past. 

Conclusions.—In summation of this subject Schuchert 
Says: 


‘““The marine ‘life thermometer’ indicates vast stretches of 
time of mild to warm and equable temperatures, with but shght 
zonal differences between the equator and the poles. The great 
bulk of marine fossils are those of the shallow seas, and the evo- 
lutionary changes recorded in these ‘medals of creation’ are 
slight throughout vast leneths of time that are punctuated by 
short but decisive periods of cooled waters and great mortality, 
followed by quick evolution, and the rise of new stocks. The 
times of less warmth are the miotherm and those of greater 
heat the plrotherm periods of Ramsay. 

On the land the story of the climatic changes is different, but 
in general the equability of the temperature simulates that of 
the oceanic areas. In other words, the lands also had long- 


90 Charles Schuchert—Historical Geology, 1818-1918. 


enduring times of mild to warm climates. Into the problem 
of land climates, however, enter other factors that are absent 
in the oceanic regions, and these have great influence upon the 
climates of the continents. Most important of these is the peri- 
odie warm-water inundation of the continents by the oceans, 
causing insular climates that are milder and moister. With the 
vanishing of the floods somewhat cooler and certainly drier 
climates are produced. The effects of these periodic floods must 
not be underestimated, for the North American continent was 
variably submerged at least seventeen times, and over an area 
of from 154,000 to 4,000,000 square miles. 

When to these factors is added the effect upon the climate 
caused by the periodic rising of mountain chains, it is at once 
apparent that the lands must have had constantly varying 
climates. In general the temperature fluctuations seem to have 
been slight, but geographically the climates varied between mild 
to warm pluvial, and mild to cool arid. The arid factor has 
been of the greatest import to the organic world of the lands. 
Further, when to all of these causes is added the fact that dur- 
ing emergent periods the formerly isolated lands were connected 
by land bridges, permitting intermigration of the land floras 
and faunas, with the introduction of their parasites and parasitic 
diseases, we learn that while the climatic environment is of fun-- 
damental importance it is not the only cause for the more rapid 
evolution of terrestrial life : | 

Briefly, then, we may conclude that the markedly varying 
climates of the past seem to be due primarily to periodic changes 
in the topographic form of the earth’s surface, plus variations 
in the amount of heat stored by the oceans. The causation for 
the warmer interglacial climates is the most difficult of all to 
explain, and it is here that factors other than those mentioned 
may enter. 

Granting all this, there still seems to lie back of all these 
theories a greater question connected with the major changes in 
paleometeorology. This is: What is it that forces the earth’s 
topography to change with varying intensity at irregularly 
rhythmic intervals? . . . Are we not forced to conclude that 
the earth’s shape changes periodically in response to gravitative 
forces that alter the body-form ?’’ 


EVOLUTION. 


Modern evolution, or the theory of life continuously 
descending from life with change, may be said to have 
had its first marked development in Comte de Buffon 
(1707-1788), a man of wealth and station, yet an indus- 
trious compiler, a brilliant writer, and a popularizer of 
science. He was not, however, a true scientific investi- 


Charles Schuchert—Historical Geology, 1818-1918. 91 


gator, and his monument to fame is his Histoire Nat- 
urelle, in forty-four volumes, 1749-1804. A. 8. Packard 
in his book on Lamarck, his Life and W ork, 1901, con- 
eludes in regard to Buffon as follows: 


‘‘The impression left on the mind, after reading Buffon, is 
that even if he threw out these suggestions and then retracted 
them, from fear of annoyance or even persecution from the 
bigots of his time, he did not himself always take them seriously, 
but rather jotted them down as passing thoughts . . . They 
appeared thirty-four years before Lamarck’s theory, and though 
not epoch-making, they are such as will render the name of 
Buffon memorable for all time.’’ 


Chevalier de Lamarck (1744-1829) may justly be 
regarded as the founder of the doctrine of modern evo- 
lution. Previous to 1794 he was a believer in the fixity 
of species, but by 1800 he stood definitely in favor of 
evolution. Locy in his Biology and its Makers, 1908, 
states his theories in the following simplified form: 


_ “Variations of organs, according to Lamarck, arise in animals 
mainly through use and disuse, and new organs have their origin 
in a physiological need. A new need felt by the animal [due 
to new conditions in its life, or the environment] expresses 
itself on the organism, stimulating growth and adaptations in a 
particular direction.’ 


To Lamarck, “caeneneie ree was a simple, direct trans- 
mission of those superficial changes that arise in organs 
within the lifetime of an individual owing to use “and 
disuse.’’ This part of his theory has come to be known 

s ‘‘the inheritance of acquired characters.’’ 

Georges Cuvier (1769-1832), a peer of France, was a 
decided believer in the fixity of species and in their crea- 
tion through divine acts. In 1796 he began to see that 
among the fossils so plentiful about Paris many were of 
extinct forms, and later on that there was a succession 
of wholly extinct faunas. This at first puzzling phenom- 
enon he finally came to explain by assuming that the 
earth had gone through a series of catastrophes, of which 
the Deluge was the most recent but possibly not the last. 
With each catastrophe all life was blotted out, and a new 
though improved set of organisms was created by divine 
acts. The Cuvierian theory of catastrophism was widely 
accepted during the first half of the nineteenth century, 
and in America Louis Agassiz was long its greatest 


92 Charles Schuchert—Historical Geology, 1818-1918. 


exponent. It was this theory and the dominance of the 
brilliant Cuvier, not only in science but socially as well, 
that blotted out the far more correct views of the more 
philosophical Lamarck, who held that life throughout the 
ages had been continuous and that through individual 
effort and the inheritance of acquired characters had 
evolved the wonderful diversity of the present living 
world. 

In 1830 there was a public debate at Paris between 
Cuvier and Geoffroy Saint-Hilaire, the one holding to the 
views of the fixity of species and creation, the other that 
life is continuous and evolves into better adapted forms. 
Cuvier, a gifted speaker and the greatest debater zoolegy 
ever had, with an extraordinary memory that never 
failed him, defeated Saint-Hilaire in each day’s debate, 
although the latter was in the right. 

A book that did a great deal to prepare the English- 
speaking people for the coming of evolution was ‘‘ Ves- 
tiges of Creation,’’ published in 1844 by an unknown 
author. In Darwin’s opinion, ‘‘the work, from its power- 
ful and brillant style... has done excellent service 

in thus preparing the ground for the reception of 
analogous views.’’ This book was recommended te the 
readers of the Journal (48, 395, 1845) with the editorial 
remark that ‘‘we cannot subscribe to all of the author’s 
views.’’ 

We can probably best illustrate the opinions of Amer- 
icans on the question of evolution just before the appear- 
ance of Darwin’s great work by directing attention to 
James D. Dana’s Thoughts on Species (24, 305, 1857). 
After reading this article and others of a similar nature 
by Agassiz, one comes to the opinion that unconsciously 
both men are proving evolution, but consciously they are 
firm creationists. It is astonishing that with their 
extended and minute knowledge of living organisms and 
their philosophic type of mind neither could see the true 
significance of the imperceptible transitions between 
some species, which if they do not actually pass into, at 
least shade towards, one another. | 

Dana speaks of ‘‘the endless diversities in individu- 
als’’ that compose a species, and then states that a living » 
species, like an inorganic one, ‘‘is based on a specific 
amount or condition of concentered force defined in the 
act or law of creation.’’? Species, he says, are perma- 


Charles Schuchert—Historical Geology, 1818-1918. 93 


nent, and hybrids ‘‘cannot seriously trifle with the true 
units of nature, and at the best, can only make tempo- 
rary variations.’’ ‘‘We have therefore reason to believe 
from man’s fertile intermixture, that he is one in species: 
and that all organic species are divine appointments 
which cannot be obliterated, unless by annihilating the 
individuals representing the species.’’ 

Through the activities of the French the world was 
prepared for the reception of evolution, and now it was 
already in the minds of many advanced thinkers. In 
1860 Asa Gray sent to the editor of the Journal (29, 1) 
an article by the English botanist, Joseph D. Hooker, 
entitled ‘‘On the Origination and Distribution of 
Species,’’ with these significant remarks: 


‘<The essay cannot fail to attract the immediate and profound 
attention of scientific men . . . It has for some time been 
manifest that a re-statement of the Lamarckian hypothesis is 
at hand. We have this, in an improved and truly scientific 
form, in the theories which, recently propounded by Mr. Dar- 
win, followed by Mr. Wallace, are here so ably and altogether 
independently maintained. When these views are fully laid 
before them, the naturalists of this country will be able to 
take part in the Eaterestane discussion which they will not fail 
to call forth.’’ 


Hooker took up a study of the flora of Tasmania, of 
which the above cited article is but a chapter, with a 
view to trying out Darwin’s theory, and he now accepts 
it. He says, ‘‘Species are derivative and mutable.’’ 
‘““The limits of the majority of species are so undefin- 
able that few naturalists are agreed upon them.”’ 

Asa Gray had received from Darwin an advance copy 
of the book that was to revolutionize the thought of the 
world, and at once wrote for the Journal a Review of 
Darwin’s Theory on the Origin of Species by means of 
Natural Selection (29, 153, 1860). This is a splendid, 
eritical but just, scientific review of Darwin’s epoch- 
making book. Evidently views similar to those of the 
English-scientist had long been in the mind of Gray, for 
he easily and quickly mastered the work. He is easy on 
Dana’s Thoughts on Species, which were idealistic and 
not in harmony with the naturalistic views of Darwin. 
On the other hand, he contrasts Darwin’s views at length 
with those of the creationists as exemplified by Louis 
Agassiz, and says ‘‘The widest divergence appears.”’ 


94 Charles Schuchert—Historical Geology, 1818-1918. 


Gray says in part: 


‘‘The gist of Mr. Darwin’s work is to show that such varieties 
are gradually diverged into species and genera through natural 
selection; that natural selection is the inevitable result of the 
struggle for existence which all living things are engaged in; 
and that this struggle is an unavoidable consequence of several 
natural causes, but mainly of the high rate at which all organic 
beings tend to increase. 

Darwin is confident that intermediate forms must have 
existed; that in the olden times when the genera, the families 
and the orders diverged from their parent stocks, gradations 
existed as fine as those which now connect closely related species 
with varieties. But they have passed and left no sign. The 
geological record, even if all displayed to view, is a book from 
which not only many pages, but even whole alternate chapters 
have been lost out, or rather which were never printed from the 
autographs of nature. The record was actually made in fossil 
lithography only at certain times and under certain conditions 
(i. e., at periods of slow subsidence and places of abundant sedi- 
ment); and of these records all but the last volume is out of 
print; and of its pages only local glimpses have been obtained. 
Geologists, except Lyell, will object to this;—some of them 
moderately, others with vehemence. Mr. Darwin himself admits, 
with a candor rarely displayed on such occasions, that he should 
have expected more geological evidence of transition than he 
finds, and that all the most eminent paleontologists maintain the 
immutability of species. 

The general fact, however, that the fossil fauna of each period 
as a whole is nearly intermediate in character between the 
preceding and the succeeding faunas, is much relied on. We 
are brought one step nearer to the desired inference by the similar 
‘fact,’ insisted on by all paleontologists, that fossils from two 
consecutive formations are far more closely related to each other, 
than are the fossils of two remote formations. 

It is well said that all organic beings have been formed on two 
great laws; Unity of type, and Adaptation to the conditions of 
existence . . . Mr. Darwin harmonizes and explains them 
naturally. Adaptation to the conditions of existence is the 
result of Natural Selection; Unity of type, of unity of descent.’’ 


Gray’s article was soon followed by another one from 
Agassiz on Individuality and Specific Differences among 
Acalephs, but the running title is ‘‘Prof. Agassiz on the 
Origin of Species’? (30, 142, 1860). Agassiz stoutly 
maintains his well known views, and concludes as 
follows: 


Charles Schuchert—Historical Geology, 1818-1918. 95 


‘‘Were the transmutation theory true, the geological record 
should exhibit an uninterrupted succession of types blending 
gradually into one another. The fact is that throughout all 
geological times each period is characterized by definite specific 
types, belonging to definite genera, and these to definite families, 
referable to definite orders, constituting definite classes and 
definite branches, built upon definite plans. Until the facts of 
Nature are shown to have been mistaken by those who have col- 
lected them, and that they have a different meaning from that 
now generally assigned to them, I shall therefore consider the 
transmutation theory as a scientific mistake, untrue in its facts, 
unscientific in its method, and mischievous in its tendency.’’ 


Dana, in reviewing Huxley’s well known book, Man’s 
Place in Nature (35, 451, 1863), holds that man is apart 
from brute nature because man exhibits ‘‘extreme ceph- 
alization’’ in that he has arms that no longer are used 
in locomotion but go rather with the head, and because 
he has a far higher mentality and speech. As for the 
Darwinian theory, the evidence, he says, ‘‘comes from 
lower departments of life, and is acknowledged by its 
advocates to be exceedingly scanty and imperfect.’’ 

The growth of evolution is set forth in the Journal in 
Asa Gray’s article on Charles Darwin (24, 453, 1882), 
which speaks of the latter as ‘‘the most celebrated man of 
science of the nineteenth century,’’ and, in addition, as 
‘fone of the most kindly and charming, unaffected, sim- 
ple-hearted, and lovable of men.’’ In regard to the rise 
of evolution in America, more can be had from Dana’s © 
paper on Asa Gray (35, 181, 1888). Here we read, as a © 
sequel to his Thoughts on Species, that the ‘‘paper may 
be taken, perhaps, as a culmination of the past, just as 
the new future was to make its appearance.’’ Finally, 
in this connection there should be mentioned O. C. 
Marsh’s paper on Thomas Henry Huxley (50, 177, 1895), 
wherein is recorded the latter’s share in the upbuilding 
of the evolutionary theory. 

We have seen that originally Dana was a creationist, 
but in the course of his long and fruitful life he gradually 
became an evolutionist, and rather a Neo-Lamarckian 
than a Darwinian. This change may be traced in the 
various editions of his Manual of Geology, and in the last 
edition of 1895 he says his ‘‘speculative conclusions’’ of 
1852 in regard to the origin of species are not ‘‘in accord 
with the author’s present judgment.’’ ‘‘The evidence in 


96 Charles Schuchert—Historical Geology, 1818-1918. 


favor of evolution by variation is now regarded as essen- 
tially complete.’’ On the other hand, while man is 
‘‘nnquestionably’’ closely related in structure to the 
man-apes, yet he is not linked to them but stands apart, 
through ‘‘the intervention of a Power above Nature. 
. Believing that Nature exists through the will and 
ever-acting power of the Divine Being, and . . . that the 
whole Universe is not merely dependent on, but actually 
is, the Will of one Supreme Intelligence, Nature, with 
Man as its culminant species, is no longer a mystery.’’ 
In America most of the paleontologists are Neo- 
Lamarckian, a school that was developed independently 
by E. D. Cope (1840-1897) through the vertebrate evi- 
dence, and by Alpheus Hyatt (1838-1902) mainly on the 
evidence of the ammonites. They hold that variations 
and acquired characters arise through the effects of the 
environment, the mechanics of the organism resulting 
from the use and disuse of organs, etc. One of the lead- 
ing exponents of this school is A. 8. Packard, whose book 
on Lamarck, His Life and Work, 1901, fully oleae the 
doctrines of the Neo-Lamarckians. 


THe GrowtH oF INVERTEBRATE PALEONTOLOGY. 


How and by whom paleontology has been developed 
has been fully stated in the Journal in a very clear man- 
ner by Professor Marsh in his memorable presidential 
address of 1879, History and Methods of Paleontological 
Discovery (18, 323, 1879), and by Karl von Zittel in his 
most interesting book, History of Geology and Palwon- 
tology, 1901. In this discussion we shall largely follow 
Marsh. 

The science of paleontology has passed through four 
periods, the first of them the long Mystic period extend- 
ing up to the beginning of the seventeenth century, when 
the idea that fossils were once living things was only 
rarely perceived. The second period was the Diluvial 
period of the eighteenth century, when nearly everyone 
regarded the fossils as remains of the Noachian deluge. 
With the beginnings of the nineteenth century there 
arose in western Eur ope the knowledge that fossils are 
the ‘‘medals of creation’’ and that they have a chrono- 
genetic significance; also that life had been periodically 
destroy ed. thr ough world-wide convulsions in nature. 
From about 1800 to 1860 was the time of the creationists 


Charles Schuchert—Historical Geology, 1818-1918. 97 


and eatastrophists, which may be known as the Catas- 
trophic period. The fourth period began in 1860 with 
Darwin’s Origin of Species. Since that time the theory 
of evolution has pervaded all work in paleontology, and 
accordingly this time may be enone as the Evolutionary 
neriod. 

Mystic Period.—The NEvetic period in paleontology 
begins with the Greeks, five centuries before the present 
era, and continues down to the beginning of the seven- 
teenth century of our time. Some correctly saw that the 
fossils were once living marine animals, and that the sea 
had been where they now occur. Others interpreted fos- 
sil mammal bones as those of human giants, the Titans, 
but the Aristotelian view that they were of spontaneous 
generation through the hidden forces of the earth domi- 
nated all thought for about twenty centuries. 

In the sixteenth century canals were being dug in 
Northern Italy, and the many fossils so revealed led to a 
fierce discussion as to their actual nature. Leonardo da 
Vine (1452-1519) opposed the commonly accepted view 
of their spontaneous generation and said that they were 
the remains of once living animals and that the sea had 
been where they occur. ‘‘You tell me,’’ he said, ‘‘that 
Nature and the influence of the stars have formed these 
shells in the mountains; then show me a place in the 
mountains where the stars at the present day make shelly 
forms of different ages, and of different species in the 
same place.’’ However, nothing came of his teachings 
and those of his countryman Fracastorio (1483-1553), 
who further ridiculed the idea that they were the 
remains of the deluge. The first mineralogist, Agricola, 
described them as minerals—fossilia—and said that they 
arose in the ground from fatty matter set in fermenta- 
tion by heat. Others said that they were freaks of 
nature. Martin Lister (1638-1711) figured fossils side 
by side with living shells to show that they were extinct 
forms of life. In the seventeenth century, and especially 
in Italy and Germany, many books were published on 
fossils, some with illustrations so accurate that the 
' species can- be recognized to-day. Finally, toward 
the close of this century the influence of Aristotle and the 
scholastic tendency to disputation came more or less to 
an end. Fossils were already to many naturalists once 
living plants and animals. Marsh states: ‘‘The many 


Am. Jour. Sc1.—FourtH Srrigs, Vou. XLVI, No. 271.—Jury, 1918. 
4 


98 Charles Schuchert—Mistorical Geology, 1818-1918. 


collections of fossils that had been brought together, and 
the illustrated works that had been published about them, 
were a foundation for greater progress, and, with the 
eighteenth century, the second period in the history of 
paleontology began.’’ 

Diluvial Period—During the eighteenth century many 
more books on fossils were published in western Europe, 
and now the prevalent explanation was that they were 
the remains of the Noachian deluge. For nearly a cen- 
tury theologians and laymen alike took this view, and 
some of the books have become famous on this account, 
but the diluvial views sensibly declined with the close 
of the eighteenth century. 

The true nature of fossils had now been clearly deter- 
mined. They were the remains of plants and. animals, 
deposited long before the deluge, part in fresh water and 
partinthe sea. ‘‘Some indicated a mild climate, and some 
the tropics. That any of these were extinct species, was 
as yet only suspected.’’ Yet before the close of the cen- 
tury there were men in England and France who pointed 
out that different formations had different fossils and 
that some of them were extinct. These views then led to 
many fantastic theories as to how the earth was formed— 
dreams, most of them have been called. Marsh says: 


‘‘The dominant idea of the first sixteen centuries of the 
present era was, that the universe was made for Man. This was 
the great obstacle to the correct determination of the position 
of the earth in the universe, and, later, of the age of the earth. 

: In a superstitious age, when every natural event is 
referred to a supernatural cause, science cannot live 3 
Searcely less fatal to the growth of science is the age of Author- 
ity, as the past proves too well. With freedom of thought, came 
definite knowledge, and certain progress;—but two thousand 
years was long to wait.”’ 


One of the most significant publications of this period 
was Linneus’s Systema Nature, which appeared in 1735. 
In this work was introduced binomial nomenclature, or 
the system of giving each plant and animal species a 
generic and specific name, as Felis leo for the lion. The 
system was, however, not established until the tenth 
edition of the work in 1758, which became the starting 
point of zoological nomenclature. Since then there has 
been added another canon, the law of priority, which 


Charles Schuchert—Historical Geology, 1818-1918. 99 


holds that the first name applied to a given form shall 
stand against all later names given to the same organism. 

Catastrophic Period —With the beginning of the nine- 
teenth century there started a new era in paleontology, 
and this was the time when the foundations of the science 
were laid. The period continued for six decades, or until 
the time of the Origin of Species. Marsh says that now 
‘‘method replaced disorder, and systematic study super- 
seded casual observation.’’ Fossils were accurately 
determined, comparisons were made with living forms, 
and the species named according to the binomial system. 
However, every species, recent and extinct, was regarded 
as a separate creation, and because of the usually sharp 
separation of the superposed fossil faunas and floras, 
these were held to have been destroyed through a series 
of periodic catastrophes of which the Noachian deluge 
was the last. 

Lamarck between 1802 and 1806 described the Tertiary 
shells of the Paris basin. Comparing them with the liv- 
ing forms, he saw that most of the fossils were of extinct 
species, and in this way he came to be the founder of 
modern invertebrate paleontology. He also maintained 
after 1801 that life has been continuous since its origin 
and that nature has been uniform in the course of its 
development. Marsh adds: 


‘““His researches on the invertebrate fossils of the Paris Basin, 
although less striking, were not less important than those of 
Cuvier on the vertebrates; while the conclusions he derived from 
them form the basis of modern biology.’’ 

‘‘Lamarck was the prophetic genius, half a century in advance 
of his time.’’ 


Cuvier established comparative anatomy and verte- 
brate paleontology, and was one of the first to point out 
that fossil animals are nearly all extinct forms. He 
came to the latter conclusion in 1796 through a study of 
fossil elephants found in Europe. ‘‘Cuvier enriched 
the animal kingdom by the introduction of fossil forms 
among the living, bringing all together into one compre- 
hensive system.’’ This opened to him entirely new 
views respecting the theory of the earth, and he devoted 
more than twenty-five years to developing the theories 
of special creation and catastrophism, deseribed in his 
Discourse on the Revolutions of the Surface of the Globe. 
‘With all his knowledge of the earth, he could not free 


100 Charles Schuchert—Historical Geology, 1818-1918. 


himself from tradition, and beleved in the universality 
and power of the Mosaic deluge. Again, he refused to 
admit the evidence brought forward by his distinguished 
colleagues against the permanence of species, and used 
all his great influence to crush out the doctrine of evolu- 
tion, then first proposed’’ (Marsh). 

In England it was William Smith (1769-1839) who 
independently discovered the chronogenetic significance 
of fossils, and in their stratigraphic superposition indi- 
cated the way for the study of historical geology. He 
first published on this matter in 1799, but his completed 
statements came in works entitled ‘‘Strata identified by 
Organized Fossils,’’? 1816-1820, and ‘‘Stratigraphical 
_ System of Organized Fossils,’’ 1817. 

Invertebrate paleontology in America during the 
Catastrophic period had its beginning in Lesueur, who 
in 1818 described the Ordovician gastropod Maclurites 
magna. All of the paleontologists of this time were sat- 
isfied to describe species and genera and to ascertain in a 
broad way the stratigraphic significance of the fossil 
faunas and floras. James Hall in 1854 (17, 312) knew of 
1588 species, described and undescribed, in the New York 
system, while in England Morris listed in that year 8300 
Paleozoic forms. In 1856 Dana recites the known fossil 
species as follows (22, 333): The whole number of 
known American species of animals of the Permian to 
Recent is about 2000; while in Britain and Europe, there 
were over 20,000 species. In the Permian we have none, 
while Europe has over 200 species. In the Triassic we 
have none, Europe 1000 species; Jurassic 60, Kurope 
over 4000; Cretaceous 350 to 400, Europe about 6000; 
Tertiary hardly 1500, Europe about 8000. Since that 
time nearly all of the larger American Paleozoic faunas 
have been developed, but there are thousands of species 
yet to be described. Who the more prominent American 
paleontologists of this period were has been told in the 
section on the development of the geological column. 

The grander paleontologic results of the Catastrophic 
period have been so well stated by Marsh that it is worth 
our while to repeat them here: 

‘It had now been proved beyond question that portions at 
least of the earth’s surface had been covered many times by the 
sea, with alternations of fresh water and of land; that the strata 
thus deposited were formed in succession, the lowest of the series 


ea ee ee eee 


Charles Schuchert—Historical Geology, 1818-1918. 101 


being the oldest; that a distinct succession of animals and 
plants had inhabited the earth during the different geological 
periods; and that the order of succession found in one part of 
the earth was essentially the same in all. More than 30,000 new 
species of extinct animals and plants had now been described. 
It had been found, too, that from the oldest formations to the 
most recent, there had been an advance in the grade of life, both 
animal and vegetable, the oldest forms being among the simplest, 
and the higher forms successively making their appearance. 

It had now become clearly evident, moreover, that the fossils 
from the older formations were all extinct species, and that only 
in the most recent deposits were there remains of forms still 
living . . . Another important conclusion reached, mainly 
through the labors of Lyell, was, that the earth had not been 
subjected in the past to sudden and violent revolutions; but the 
ereat changes wrought had been gradual, differing in no essen- 
tial respect from those still in progress. Strangely enough, the 
corollary to this proposition, that life, too, had been continuous 
on the earth, formed at that date no part of the common stock 
of knowledge. In the physical world, the great law of ‘cor- 
relation of forces’ had been announced, and widely accepted; 
but in the organic world, the dogma of the miraculous creation 
of each separate species still held sway.”’ 


Evolutionary Period—tThis period begins with 1860 
and the publication of Darwin’s Origin of Species (late 
in 1859). Itis the period of modern paleontology, and is 
dominated by the belief that universal laws pervade not 
only inorganic matter, but all life as well. Louis Agas- 
siz had been in America fourteen years when Darwin’s 
book appeared, and his wonderful influence in bringing 
the zoology of our country to a high stand and the 
further influence he exerted through his students was 
bound to react beneficially on invertebrate paleontology. 
Shortly after the beginning of this period, or in 1867, 
Alpheus Hyatt, one of Agassiz’s students, began to apply 
the study of embryology to fossil cephalopods, showing 
clearly that these shells retain a great deal of their 
erowth stages or ontogeny. This method of study was 
then followed by R. T. Jackson, C. EK. Beecher, and J. 
P. Smith, and has been productive of natural classifica- 
tions of the Cephalopoda, Brachiopoda, Trilobita, and 
Echinoidea. 

The dominant invertebrate paleontologist of this 
period was of course James Hall, who deseribed about 
5000 species of American Paleozoic fossils. He also 


102 Charles Schuchert—Mistorical Geology, 1818-1918. 


built up the New York State Museum, while around his 
private collections of fossils have been developed the 
American Museum of Natural History in New York City 
and the Walker Museum at the University of Chicago. 
In his most important laboratory of paleontology at 
Albany, there have been trained either wholly or in 
part the following paleontologists: EF. B. Meek, C. A. 
White, R. P. Whitfield, C. D. Walcott, C. EK. Beecher, 
John M. Clarke, and Charles Schuchert. 

In Canada, through the work of the Geological Survey 
of the Dominion, came the paleontologists Hlkanah 
Billings and, later on, J. F’. Whiteaves. The ‘‘father of 
Canadian paleontology,’’ Sir William Dawson, who 
developed independently, was active in all branches of — 
the science and did much to unravel the geology of 
eastern Canada. No organism has been more discussed 
and more often rejected and accepted as a fossil than his 
‘‘dawn animal of Canada,’’ Hozoon canadense, first 
described in 1865. His son, George M. Dawson, was one 
of the directors of the Geological Survey of Canada. 
Finally the extensive paleontology of the Cambrian of 
Canada was worked out by another self-made paleontolo- 
gist, G. F. Matthew. 

Paleobotany.—American paleobotany was developed 
during this, the fourth period, through the state and 
national surveys, first in Leo Lesquereux, a Swiss stu- 
dent induced by Agassiz to come to America, and in J. 8. 
Newberry. The second generation of paleobotanists is 
represented by Lester F. Ward and W. N. Fontaine, 
and the third generation, the present workers, includes 
F’. H. Knowlton, David White, Arthur Hollick, and EK. W. 
Berry. A new line of paleobotanical work, the histology 
of woody but pseudomorphous remains, has been devel- 
oped by G. R. Wieland. 

The grander results of the study of paleontology dur- 
ing the evolutionary period may be summed up with the 
conclusions of Marsh: 


‘“One of the main characteristics of this epoch is the belief 
that all life, living and extinct, has been evolved from simple 
forms. Another prominent feature is the accepted fact of the 
great antiquity of the human race. These are quite sufficient 
to distinguish this period sharply from those that preceded it. 

Charles Darwin’s work at once aroused attention, and brought 
about in scientific thought a revolution which ‘‘has influenced 


Charles Schuchert—Historical Geology, 1818-1918. 103 


paleontology as extensively as any other department of science 

In the [previous period] species were represented inde- 
pendently by parallel lLnes; in the present period, they are 
indicated by dependent, branching lines. The former was the 
analytic, the latter is the synthetic period.’’ 


Synthetic Period—What is to be the next trend in 
paleontology? Clearly it is to be the Synthetic period, 
one that Marsh in 1879 indicated in these words: ‘‘ But 
if we are permitted to continue in imagmation the rap- 
idly converging lines of research pursued to-day, they 
seem to meet at the point where organic and inorganic 
nature become one. That this point will yet be reached, 
I cannot doubt.’’ 

This Synthetic period, foreshadowed also in Herbert 
Spencer’s Synthetic Philosophy, has not yet arrived, but 
before long another great leader will appear. We have 
the prophecy of his coming in such books as The Fitness 
of the Environment, by Lawrence J. Henderson, 19135; 
The Origin and Nature of Life, by Benjamin Moore, 
1913; The Organism as a Whole, by Jacques Loeb, 1916; 
and The Origin and Evolution of Life, by Henry F. 
Osborn, 1917. 

In all nature, inorganic and organic, there is continuity 
and consistency, beauty and design. We are beginning 
to see that there are eternal laws, ever interacting and 
resulting in progressive and regressive evolutions. The 
realization of these scientific revelations kindles in us a 
desire for more knowledge, and the grandest revelations 
are yet before us in the synthesis of the sciences. 


104 Gregory—Progress im Interpretation of Land Forms. 


Arr. IIL—A Century of Geology—Steps of Progress in 
the Interpretation of Land Forms; by Hersert KH. 
GREGORY. 


The essence of physiography is the belief that land 
forms represent merely a stage in the orderly develop- 
ment of the earth’s surface features; that the various 
dynamic agents perform their characteristic work 
throughout all geologic time. The formulation of prin- 
ciple and processes of earth sculpture was, therefore, 
impossible on the hypothesis of a ready-made earth 
whose features were substantially unchangeable, except 
when modified by catastrophic processes. In 1821, J. W. 
Wilson wrote in this Journal: ‘‘Is it not the best theory 
of the earth, that the Creator, in the beginning, at least 
at the general deluge, formed it with all its present grand 
characteristic features?’’! If so, a search for causes is 
futile, and the study of the work performed by streams 
and glaciers and wind is unprofitable. The belief in the 
Deluge as the one great geological event in the history of 
the earth has brought it about that the speculations of 
Aristotle, Herodotus, Strabo, and Ovid, and the illus- 
trious Arab, Avicenna (980-1037), unchecked by appeal 
to facets but also unopposed by priesthood or popular 
prejudice, are nearer to the truth than the intolerant con- 
troversial writings of the intellectual leaders whose 
touchstone was orthodoxy. A few thinkers of the 16th 
century revolted against the interminable repetition of 
error, and Peter Severinus (1571) advised his students: 
‘‘Burn up your books ... buy yourselves stout shees, 
get away to the mountains, search the valleys, the 
deserts, the shores of the seas. . . . In this way and no 
other will you arrive at a knowledge of things.’’ But 
the thorough-goine ‘‘diluvialist’’ who believed that a 
million species of animals could occupy a 450-foot 
Ark, but not that pebbles weathered from rock or that 
rivers erode, had no use for his powers of observation. 

Sporadic germs of a science of land forms scattered 
through the literature of the 17th and. 18th centuries 
found an unfavorable environment and produced incon- 
spicuous growths. Even their sponsors did little to 


‘Numbers refer to titles listed in the Bibliography at the end of this 
article. - 


Gregory—Progress in Interpretation of Land Forms, 105 


cultivate them. Steno (1631-1687) mildly suggested that 
surface sculpturing, particularly on a small scale, is 
largely the work of running water, and Guettard (1715- 
1786), a truly great mind, grasped the fundamental prin- 
ciples of denudation and successfully entombed his views 
as well as his reputation in scores of books’ and volumes 
of cumbrous diffuse writing. 

At the beginning of the 19th century a sufficient body of 
principles had been established to justify the recognition 
of an earth science, geology, and the 195 volumes of the 
Journal thus far published carry a large part of the 
material which has won approval for the new science and 
given prominence to American thought. From the pages 
in the Journal, the progress of geology may be illustrated 
by tracing the fluctuation in the development of fact and 
theory as relates to valleys and glacial features, the sub- 
jects to which this chapter is devoted. 


THE INTERPRETATION OF VALLEYS. 
The Pioneers. 


Desmarest (1725-1815) might be styled the father of 
physiography. By concrete examples and sound induc- 
tion he established (1774) the doctrine that the valleys of 
central France are formed by the streams which occupy 
them. He also made the first attempt to trace the his- 
tory of a landscape through its successive stages on the 
basis of known causes. His methods and reasoning are 
practically identical with those of Dutton working in the 
ancient lavas of New Mexico; and Whitney’s description 
of the Table Mountains of California might well have 
appeared in Desmarest’s memoirs.” The teachings of 
Desmarest were strengthened and expanded by DeSaus- 
sure (1740-1799), the sponsor for the term, ‘‘Geology,”’ 
(1779) who saw in the intimate relation of Alpine 
streams and valleys the evidence of erosion by running 
water (1786). 

The work of these acknowledged leaders of geological 
thought attracted singularly little attention on the Con- 
tinent, and Lamarck’s volume on denudation (Hydro- 
éologie), which appeared in 1802, although an important 
contribution, sank out of sight. But the seed of the 
French school found fertile ground in Edinburgh, the 
center of the geological world during the first quarter of 


106 Gregory—Progress in Interpretation of Land Forms. 


the 19th century. Hutton’s ‘‘Theory of the Earth, with 
Proofs and Illustrations,’’ in which the guidance of 
DeSaussure and Desmarest is gratefully acknowledged, 
appeared in 1795. The original publication aroused only 
local interest, but when placed in attractive form by Play- 
fair’s ‘‘Ilustrations of the Huttonian Theory’’ (1802), 
the problem of the origin and development of land forms 
assumed a commanding position in geological thought. 
Hutton was peculiarly fortunate in his environment. He 
had the support and assistance of a group.of able scien- 
tific colleagues as well as the bitter opposition of Jameson 
and of the defenders of orthodoxy. His views were 
discussed in scientific publications and found their way to 
literary and theological journals. Hutton’s conception 
of the processes of land sculpture—slow upheaving and 
slow degradation of mountains, differential weathering, 
and the carving of valleys by streams—has a very 
modern aspect. Playfair’s book would scarcely be out of 
place in a 20th century class room. The following para- 
eraphs are quoted from it :° 


‘“,..A river, of which the course is both serpentine and 
deeply excavated in the rock, 1s among the phenomena, by 
which the slow waste of the land, and also the cause of that 
waste, are most directly pointed out. 

The structure of the vallies among mountains, shews clearly to 
what cause their existence is to be ascribed. Here we have first 
a large valley, communicating directly with the plain, and wind- 
ing between high ridges of mountains, while the river in the 
bottom of it descends over a surface, remarkable, in such a 
scene, for its uniform declivity. Into this, open a multitude of 
transverse or secondary vallies, intersecting the ridges on either 
side of the former, each bringing a contribution to the main 
stream, proportioned to its magnitude; and, except where a 


cataract now and then intervenes, all having that nice -adjust-_ 


ment in their levels, which is the more wonderful, the greater 
the irregularity of the surface. These secondary vallies have 
others of a smaller size opening into them; and, among moun- 
tains of the first order, where all is laid out on the greatest scale, 
these ramifications are continued to a fourth, and even a fifth, 
each diminishing in size as it inereases in elevation, and as its 
supply of water is less. Through them all, this law is in gen- 
eral observed, that where a higher valley joins a lower one, of 
the two angles which it makes with the latter, that which is 
obtuse 1s always on the descending side; . . . what else but the 
water itself, working its way through obstacles of unequal 


q 
q 


Gregory—Progress in Interpretation of Land Forms, 107 


resistance, could have opened or kept up a communication 
between the inequalities of an irregular and alpine surface .. . 

... The probability of such a constitution [arrangement of 
valleys] having arisen from another cause, is, to the probability 
of its having arisen from the running of water, in such a pro- 
portion as unity bears to a number infinitely great. 

... With Dr. Hutton, we shall be disposed to consider those 
ereat chains of mountains, which traverse the surface of the 
elobe, as cut out of masses vastly greater, and more lofty than 
any thing that now remains. 

From this gradual change of lakes into rivers, it follows, that 
a lake is but a temporary and accidental condition of a river, 
which is every day approaching to its termination; and the 
truth of this is attested, not only by the lakes that have existed, 
but also by those that continue to exist.’’ 


Steps Backward. 


Kven Hutton’s clear reasoning, firmly buttressed by 
concrete examples, was insufficient to overcome the belief 
in ready-made or violently formed valleys and original 
corrugations and irregularities of mountain surface. 
The pages of the Journal show that the principles laid 
down by Playfair were too far in advance of the times to 
secure general acceptance. In the first volume of the 
Journal, the gorge of the French Broad River is assigned 
by Kain to ‘‘some dreadful commotion in nature which 
probably shook these mountains to their bases,’’* and 
the gorge of the lower Connecticut is considered by 
Hitcheock (1824)° as a breach which drained a series of 
lakes ‘‘not many centuries before the settlement of this 
country.’’ The prevailing American and English view 
for the first quarter of the 19th century is expressed in 
the reviews in this Journal, where the well-known 
conclusions of Conybeare and Phillips that streams are 
incompetent to excavate valleys are quoted with approval 
and admiration is expressed for Buckland’s famous 
‘‘Reliquie Diluviane,’’a 300-page quarto volume devoted 
to proof of a deluge. The professor at Yale, Silliman, 
and the professor at Oxford, Buckland, saw that an 
acceptance of Hutton’s views involved a repudiation of 
the Biblical flood, and much space is devoted to combating 
these ‘‘erroneous’’ and ‘‘unscientifie’’ views. For exam- 
ple, Buckland says :° 


‘<. . The general belief is, that existing streams, avalanches 
and lakes, bursting their barriers, are sufficient to account for 


108 Gregory—Progress in Interpretation of Land Forms. 


all their phenomena, and not a few geologists, especially those 
of the Huttonian school, at whose head is Professor Playfair, 
have till recently been of this opinion. . . . But it is now very 
clear to almost every man, who impartially examines the facts 
in regard to existing vallies, that the causes now in action, men- 
tioned above, are altogether inadequate to their production; 
nay, that such a supposition would involve a physical impossi- 
bility. We do not believe that one-thousandth part of our 
present vallies were excavated by the power of existing streams. 
. .. In very many eases of large rivers, it is found, that so far 
from having formed their own beds, they are actually in a grad- 
ual manner filling them up. 

Again; how happens it that the source of a river is frequently 
below the head of a valley, if the river excavated that valley? 

The most powerful argument, however, in our opinion, 
against the supposition we are combating, is the phenomena of 
transverse and longitudinal valleys; both of which could not 
possibly have been formed by existing streams.’’ 


Phillips writes in 1829:" ‘‘The excavation of valleys 
can be ascribed to no other cause than a great flood of 
water which overtopped the hills, whose summits those 
valhes descend.’’ : 

Faith in Noah’s flood as the dominant agent of erosion 
rapidly lost ground through the teaching of Lyell after 
1830, but the theory of systematic development of land- 
scapes by rivers gained little. In fact, Scrope in 1830,° 
in showing that the entrenched meanders of the Moselle 
prove gradual progressive stream work was in advance 
of his English contemporary. Judged by contributions 
to the Journal, Lyell’s teaching served to standardize 
American opinion of earth sculpture somewhat as fol- 
lows: The ocean is the great valley maker, but rivers 
also make them; the position of valleys is determined by 
original or renewed surface inequalities or by faulting; 
exceptional occurrences—earthquakes, bursting of lakes, 
upheavals and depressions—have played an important 
part. Hayes (1839)° thought that the surface of New 
York was essentially an upraised sea-bottom modified by 
erosion of waves and ocean currents. Sedgwick (1838)?° 
considered high-lying lake basins proof of valleys which 
were shaped under the sea. Many of the valleys in the 
Chilan Cordillera were thought by Darwin (1844) to 
have been the work of waves and tides, and water gaps 
are ascribed to currents ‘‘bursting through the range at 
those points where the strata have been least inclined 


Gregory—Progress wn Interpretation of Land Forms. 109 


and the height consequently is less.’’ Speaking of the 
magnificent stream-cut canyons of the Blue Mountains 
of New South Wales, gorges which lead to narrow exits 
through monoclines, Darwin says: ‘‘To attribute these 
hollows to alluvial action would be preposterous.’’!! 

The influence of structure in the formation of valleys 
is emphasized by many contributors® to the Journal. 
Hildreth in 1836, in a valuable paper,!* which is perhaps 
the first detailed topographic description of drainage in 
folded strata, expresses the opinion that the West Vir- 
ginia ridges and valleys antedated the streams and that 
water gaps though cut by rivers involve pre-existing 
lakes. Geddes (1826)! denied that Niagara River cut its 
channel and speaks of valleys which ‘‘were valleys e’er 
moving spirit bade the waters flow.’’ Conrad (1839)1+ 
discussed the structural control of the Mohawk, the 
Ohio, and the Mississippi, and Lieutenant Warren 
(1859)*° coneluded that the Niobrara must have orig- 
inated in a fissure. According to Lesley (1862)?® 
the course of the New River across the Great Val- 
ley and into the Appalachians ‘‘striking the escarp- 
ment in the face’’ is determined by the junction of 
anticlinal structures on the north with faulted mono- 
chines toward the south; a conclusion in harmony 
with the views of Edward Hitchcock (1841)'* that major 
valleys and mountain passes are structural in origin and 
that even subordinate folds and faults may determine 
minor features. ‘‘Is not this a beautiful example of 
prospective benevolence on the part of the Deity, thus, 
by means of a violent fracture of primary moun- 
tains, to provide for easy intercommunication through 
alpine regions, countless ages afterwards!’’ The extent 
of the wandering from the guidance of DeSaussure and 
Playfair after the lapse of 50 years is shown by students 
of Switzerland. Alpine valleys to Murchison (1851) 
were bays of an ancient sea; Schlaginweit (1852) found 
regional and local complicated crustal movements a satis- 
factory cause, and Forbes (1863) saw only glaciers. 


Valleys Formed by Rivers. 


One strong voice before 1860 appears to have called 
Americans back to truths expounded by Desmarest and 
Hutton. Dana in 1850!5 amply demonstrated that val- 
leys on the Pacific Islands owe neither their origin, 


110 Gregory—Progress in Interpretation of Land Forms. 


position or form to the sea or to structural factors. 
They are the work of existing streams which have eaten 
their way headwards. Even the valleys of Australia 
cited by Darwin as type examples of ocean work are 
shown to be products of normal stream work. Dana 
went further and gave a permanent place to the Hut- 
tonian idea that many bays, inlets, and fiords are but the 
drowned mouths of stream-made valleys. In the same 
volume in which these conclusions appeared, Hubbard 
(1850)1® announced that in New Hampshire the ‘‘ deepest 
valleys are but valleys of erosion.’’ The theory that 
valleys are excavated by streams which occupy them 
was all but universally accepted after F. V. Hayden’s 
description”? of Rocky Mountain gorges (1862) and New- 
berry’s interpretation of the canyons of Arizona (1862) ; 
but the scientific world was poorly prepared for New- 
berry’s statement :*! 


‘Like the great canons of the Colorado, the broad valleys 
bounded by high and perpendicular walls belong to a vast system 
of erosion, and are wholly due to the action of water... . The 
first and most plausible explanation of the striking surface fea- 
tures of this region will be to refer them to that embodiment of 
resistless power—the sword that cuts so many geological knots— 
voleanic force. The Great Canon of the Colorado would be 
considered a vast fissure or rent in the earth’s crust, and the 
abrupt termination of the steps of the table-lands as marking 
lines of displacement. This theory though so plausible. and so 
entirely adequate to explain all the striking phenomena, lacks 
a single requisite to acceptance, and that is truth.’’ 


With such stupendous examples in mind, the dictum 
of Hutton seemed reasonable: ‘‘there is no spot on which 
rivers may not formerly have run.’’ 


Denudation by Rivers. 


The general recognition of the competency of streams 
to form valleys was a necessary prelude to the broader 
view expressed by Jukes (1862)? 


‘“‘The surfaces of our present lands are as much carved and» 
sculptured surfaces as the medallion carved from the slab, or the 
statue sculptured from the block. They have been gradually 
reached by the removal of the rock that once covered them, and 
are themselves but of transient duration, always slowly wasting 
from decay.’’ 


Gregory—Progress in Interpretation of Land Forms. 111 


Contributions to the Journal between 1850 and 1870 
reveal a tendency to accept greater degrees of erosion 
by rivers, but the necessary end-product of subaérial 
erosion—a plain—is first clearly defined by Powell in 
1875.*? In formulating his ideas Powell introduced the 
term ‘‘base-level,’’? which may be called the germ word 
out of which has grown the ‘‘cycle of erosion,’’ the 
master key of modern physiographers. The original 
definition of base-level follows: 


‘““We may consider the level of the sea to be a grand base- 
level, below which the dry lands cannot be eroded; but we may 
also have, for local and temporary purposes, other base-levels of 
erosion, which are the levels of the beds of the principal streams 
which carry away the products of erosion. (I take some liberty 
in using the term ‘level’ in this connection, as the action of a 
running stream in wearing its channel ceases, for all practical 
purposes, before its bed has quite reached the level of the lower 
end of the stream. What I have ealled the base-level would, in 
fact, be an imaginary surface, inclining slightly in all its parts 
toward the lower end of the principal stream draining the area 
through which the level is supposed to extend, or having the 
inclination of its parts varied in direction as determined by 
tributary streams.) ’’ 


Analysis of Powell’s view has given definiteness to the 
distinction between ‘‘base-level,’’ an imaginary plane, 
and ‘‘a nearly featureless plain,’’ the actual land surface 
produced in the last stage of subaérial erosion. 

Following their discovery in the Colorado Plateau 
Province, denudation surfaces were recognized on the 
Atlantic slope and discussed by McGee (1888) ,?4 ina paper 
notable for the demonstration of the use of physiographic 
methods and criteria in the solution of stratigraphic 
problems. Davis (1889)?° described the upland of 
southern New England developed during Cretaceous 
time, introducing the term ‘‘peneplain,’’ ‘‘a nearly fea- 
tureless plain.’’ The short-lived opposition to the 
theory of peneplanation indicates that in America at least 
the idea needed only formulation to insure acceptance. 

It is interesting to note that surfaces now classed as 
peneplains were fully described by Percival (1842),7° 
who assigned them to structure, and by Kerr (1880),?7 
who considered glaciers the agent. In Europe ‘‘plains 
of denudation’’ have been clearly recognized by Ramsay 
(1846), Jukes (1862), A. Geikie (1865), Foster and Top- 


112 Gregory—Progress in Interpretation of Land Forms. 


ley (1865), Maw (1866), Wynne (1867), Whitaker (1867), 
Macintosh (1869), Green (1882), Richthofen (1882), but 
all of them were looked upon as products of marine work, 
and writers of more recent date in Kingland seem reluc- 
tant to give a subordinate place to the erosive power of 
waves. Americans, on the other hand, have been think- 
ing in terms of rivers, and the great contribution of the 
American school is not that peneplains exist, but that 
they are the result of normal subaérial erosion. More 
precise field methods during the past decade have 
revealed the fact that no one agent is responsible for the 
land forms classed as peneplains; that not only rivers 
and ocean, but ice, wind, structure, and topographic 
position must be taken into account. 

The recognition of rivers as valley-makers and of the 
final result of stream work necessarily preceded an 
analysis of the process of subaérial erosion. The first 
and last terms were known, the intermediate terms and 
the sequence remained to be established. A significant 
contribution to this problem was made by Jukes (1862).?” 


**, . . I believe that the lateral valleys are those which were 
first formed by the drainage running directly from the crests of 
the chains, the longitudinal ones being subsequently elaborated 
along the strike of the sotter or more erodable beds exposed on 
the flanks of those chains.’ 


Powell’s discussion of antecedent and consequent 
drainage (1875) and Gilbert’s chapter on land sculpture 
in the Henry Mountain report (1880) are classics, and 
McGee’s contribution?* contains significant. suggestions. 
but the master papers are by Davis,?® who introduces an 
analysis of land forms based on str ucture and age by the 
statement: 


‘‘Being fully persuaded of the gradual and systematic evolu- 
tion of topographical forms it is now desired . . . to seek the 
causes of the location of streams in their present courses; to go 
back if possible to the early date when central Pennsylvania was 
first raised from the sea, and trace the development of the several 
river systems then implanted upon it from their ancient begin- | 
ning to the present time.”’ 


That such a task could have been undertaken a quarter 
of a century ago and to-day considered a part of every- 
day field work shows how completely the lost ground of a 


Gregory—Progress nm Interpretation of Land Forms. 118 


half-century has been regained and how: rapid the 
advance in the knowledge of land sculpture since the 
eanyons of the Colorado Plateau were interpreted. 


FEATURES RESULTING FROM GLACIATION. 
The Problem Stated. 


Early in the 19th century when speculation regarding 
the interior of the earth gave place in part to observations 
of the surface of the earth, geologists were confronted 
with perhaps the most difficult problem in the history of 
the science. As stated by the editor of the Journal 
im 1821 ;%° 


‘“The almost universal existence of rolled pebbles, and boulders 
of rock, not only on the margin of the oceans, seas, lakes, and 
rivers; but their existence, often in enormous quantities, in 
situations quite removed from large waters; inland,—in high 
banks, imbedded in strata, or scattered, occasionally, in pro- 
fusion, on the face of almost every region, and sometimes on the 
tops and declivities of mountains, as well as in the vallies 
between them; their entire difference, in many cases, from the 
rocks in the country where they le—rounded masses and peb- 
bles of primitive rocks being deposited in secondary and alluvial 
regions, and vice versa; these and a multitude of similar facts 
have ever struck us as being among the most interesting of 
geological occurrences, and as being very inadequately accounted 
for by existing theories.’’ 


The phenomena demanding explanation — jumbled 
masses of ‘‘diluvium,’’ polished and striated rock, 
bowlders distributed with apparent disregard of topog- 
raphy—were indeed startling. Even Lyell, the great 
exponent of uniformitarianism, appears to have lost faith 
in his theories when confronted with facts for which 
known causes seemed inadequate. The interest aroused 
is attested by 31 titles in the Journal during its first two 
decades, articles which include speculations unsupported 
by logic or fact, field observation unaccompanied by 
explanation, field observation with fantastic explanation, 
ex-cathedra pronouncements by prominent men, sound 
reasoning from insufficient data, and unclouded recogni- 
tion of cause and effect by both obscure and prominent 
men. With little knowledge of glaciers, areal geology, 
or of structure and composition of drift, all known forces 
were called in: normal weathering, catastrophic floods, 


liz Gregory—Progress mm Interpretation of Land Forms. 


ocean currents, waves, icebergs, glaciers, wind, and even 
depositions from a primordial atmosphere (Chabier, 
1823). Human agencies were not discarded. Speak- 
ing of a granite bowlder at North Salem, New York, 
described by Cornelius (1820)*! as resting on limestone, 
Finch (1824)*? says: ‘‘it is a magnificent cromlech and 
the most ancient and venerable monument which America 
possesses.’’ In the absence of a known cause, cata- 
strophic agencies seem reasonable. 


The Deluge. 
In the seventh volume of the Journal (1824)? we read: 


‘‘After the production of these regular strata of sand, clay, 
limestone, &c. came a terrible irruption of water from the-north, 
or north-west, which in many places covered the preceding 
formations with diluvial gravel, and carried along with it those 
immense masses of granite, and the older rocks, which attest to 
the present day the destruction and ruin of a former world.’’ 


Another author remarks: 


‘“We find a mantle as it were of sand and gravel indifferently 
covering all the solid strata, and evidently derived from some 
convulsion which has lacerated and partly broken up those 
Simataren se = 


The catastrophe favored by most geologists was floods 
of water violently released—‘‘we believe,’’ says the 
editor, ‘‘that all geologists agree in imputing ... the 
diluvium to the agency of a deluge at one period or 
another.’’*+ Such conclusions rested in no small way 
upon Hayden’s well-known treatise on surficial deposits 
(1821),2° a volume which deserves a prominent place in 
American geological literature. Hayden clearly dis- 
tinguished the topographic and structural features of the 
drift but found an adequate cause in general wide-spread 
currents which ‘‘flowed impetuously across the whole 
continent... from north east to south west.’’ In review- 
ing Hayden’s book Silliman remarks: 


‘‘The general cause of these currents Mr. Hayden -coneludes to 
be the deluge of Noah. While no one will object to the propriety 
of ascribing very many, probably most of our alluvial features, 
to that catastrophe, we conceive that neither Mr. Hayden, nor 
any other man, is bound to prove the immediate physical cause 
of that vindictive infliction. 


Gregory—Progress in Interpretation of Land Forms, 115 


We would beg leave to suggest the following as a cause which 
may have aided in deluging the earth, and which, were there 
- occasion, might do it again. 

The existence of enormous caverns in the bowels of the earth, 
(so often imagined by authors,) appears to be no very extrava- 
gant assumption. It is true it cannot be proved, but in a sphere 
of eight thousand miles in diameter, it would appear in no way 
extraordinary, that many cavities might exist, which collectively, 
or even singly, might well contain much more than all our 
oceans, seas, and other superficial waters, none of which are 
probably more than a few miles in depth. If these cavities com- 
municate in any manner with the oceans, and are (as if they 
exist at all, they probably are,) filled with water, there exist, we 
conceive, agents very competent to expel the water of these cav- 
ities, and thus to deluge, at any time, the dry land.’’ 


The teachings of Hayden were favorably received by 
Hitecheock, Struder, and Hubbard, and many Europeans. 
They found a champion in Jackson, who states (1839) :°° 


‘‘From the observations made upon Mount Ktaadn, it is 
proved, that the current did rush over the summit of that lofty 
mountain, and consequently the diluvial waters rose to the height 
of more than 5,000 feet. Hence we are enabled to prove, that the 
ancient ocean, which rushed over the surface of the State, was at 
least a mile in depth, and its transporting power must have 
been greatly increased by its enormous pressure.”’ 


Gibson, a student of western geology, reaches the same 
conclusion (1836) :°7 


‘“‘That a wide-spread current, although not, as imagined, fed 
from an inland sea, once swept over the entire region between 
- the Alleghany and the Rocky Mountains is established by 
plenary proof.’’ 


Professor Sedgwick (1831) thought the sudden up- 
heaval of mountains sufficient to have caused floods 
again and again. The strength of the belief in the Bib- 
heal flood, during the first quarter of the 19th century, 
may be represented by the following remarks of Phil- 
lips. GES32).2* 


‘Of many important facts which come under the consideration 
of geologists, the ‘Deluge’ is, perhaps, the most remarkable; and 
it is established by such clear and positive arguments, that if any 
one point of natural history may be considered as proved, the 
deluge must be admitted to have happened, because it has left 
full evidence in plain and characteristic effects wpon the surface 
of the earth.’’ 


116 Gregory—Progress in Interpretation of Land Forms. 


However, the theory of deluges, whether of ocean or 
land streams, did not hold the field unopposed. In 1823, 
Granger,®® an observer whose contributions to science 
total only six pages, speaks of the striz on the shore of 
Lake Erie as 


‘‘having been formed by the powerful and continued attrition of 
some hard body. . . . To me, it does not seem possible that water 
under any circumstances, could have effected it. The flutings in 
width, depth, and direction, are as regular as if they had been 
eut out by a grooving plane. This, running water could not 
effect, nor could its operation have produced that glassy smooth- 
ness, which, in many parts, it still retains.’’ 


Hayes and also Conrad expressed similar views in the 
Journal 16 years later. 

The idea that ice was in some way concerned with the 
transportation of drift has had a curious history. The 
first unequivocal statement, based on reading and keen 
observation, was made in the Journal by Dobson in 
1826 9 . 


‘*T have had oceasion to dig up a great number of bowlders, of 
red sandstone, and of the conglomerate kind, in erecting a cotton 
manufactory; and it was not uncommon to find them worn 
smooth on the under side, as if done by their having been 
dragged over rocks and gravelly earth, in one steady position. 
On examination, they exhibit scratches and furrows on the 
abraded part; and if among the minerals composing the rock, 
there happened to be pebbles of feldspar, or quartz, (which was 
not uncommon,) they usually appeared not to be worn so much 
as the rest of the stone, preserving their more tender parts in a 
ridge, extending some inches. When several of these pebbles 
happen to be in one block, the preserved ridges were on the same 
side of the pebbles, so that it is easy to determine which part of 
the stone moved forward, in the act of wearing. 

These bowlders are found, not only on the surface, but I have 
discovered them a number of feet deep, in the earth, in the hard 
compound of clay, sand, and gravel... . 

I think we cannot account for these appearances, unless we 
call in the aid of ice along with water, and that they have been 
worn by being suspended and carried in ice, over rocks and 
earth, under water.’’ 


In Dobson’s day the hypothesis of ‘‘gigantic floods,’’ 
‘“debacles,’’ ‘‘resistless world-wide currents,’’ was so 
firmly entrenched that the voice of the observant layman 
found no hearers, and a letter from Dobson to Hitcheock 


Gregory—Progress mm Interpretation of Land Forms. 117 


written in 1837 and containing additional evidence and 
argument remained unpublished until Murchison, in 
1842, paid his respects to the remarkable work of a 
remarkable man.” 


‘“T take leave of the glacial theory in congratulating American 
science in having possessed the original author of the best 
glacial theory, though his name had escaped notice; and in 
recommending to you the terse argument of Peter Dobson, a 
previous acquaintance with which might have saved volumes of 
disputation on both sides of the Atlantic.’ 


Glaciers vs. Icebergs. 


The glacial theory makes its way into geological lit- 
erature with the development of Agassiz (1837) of the 
views of Venetz (1833) and Charpentier (1834), that the 
glaciers of the Alps once had greater extent. The bold 
assumption was made that the surface of Europe as far 
south as the shores of the Mediterranean and Caspian 
seas was covered by ice during a period immediately 
preceding the present. The kernel of the present gla- 
cial theory is readily recognizable in these early works, 
but it is wrapped in a strange husk: it was assumed that 
the Alps were raised by a great convulsion under the 
ice and that the erratics slid to their places over the 
newly made declivities. The publication of the famous 
‘‘Hitudes sur les Glaciers’’ (1840), remarkable alike for 
its clarity, its sound inductions, and: wealth of illustra- 
tions, brought the ideas of Agassiz more into prominence 
and inaugurated a 30-years’ war with the proponents of 
currents and icebergs. The outstanding objections to the 
theory were the requirement of a frigid climate and the 
demand for glaciers of continental dimensions; very 
strong objections, indeed, for the time when fossil evi- 
dence was not available, the great polar ice sheets were 
unexplored, and the distinction between till and water- 
laid drift had not been established. 

The glacial theory was cordially adopted by Buck- 
land (1841)*#2 and in part by Lyell in England but 
viewed with suspicion by Sedgwick, Whewell, and Man- 
tell. In America the response to the new idea was 
immediate. Hitchcock (1841)!* concludes an able dis- 


* Peter Dobson (1784-1878) came to this country from Preston, England, 
in 1809 and established a cotton factory at Vernon, Conn. 


118 Gregory—Progress in Interpretation of Land Forms. 


cussion with the statement: ‘‘So remarkably does it 
solve most of the phenomena of diluvial action, that I am 
constrained to believe its fundamental principles to be 
founded in truth.’’ 

The theory formed the chief topic of discussion at the 
third and fourth meetings of the Association of American 
Geologists and Naturalists (1842, 1843) under the lead 
of a committee on drift consisting of Emmons, W. B. 
Rogers, Vanuxem, Nicollet, J ackson, and J. L. Hayes. 
The result of these discussions was a curious reaction. 
Hitchcock complained that he ‘‘had been supposed to be 
an advocate for the unmodified glacial theory, but he had 
never been a believer in it,’’ and Jackson spoke for a 
number of men when he stated: 


‘“This country exhibits no proofs of the glacial theory as taught 
by Agassiz but on the contrary the general bearing of the facts 
is against that theory. ... Many eminent men incautiously 
embraced the new theory, which within two or three years from 
its promulgation, had been found utterly inadequate, and is now 
abandoned by many of its former supporters.’’ 


Out of this symposium came also the strange contribu- 
tion of H. D. Rogers (1844) ,4+ who cast aside the teach- 
ings of deduction and observation and returned to the 
views of the Medievalists. 


‘“Tf we will conceive, then, a wide expanse of waters, less per- 
haps than one thousand feet in depth, dislodged from some high 
northern or circumpolar basin, by a general lifting of that region 
of perhaps a few hundred feet, and an equal subsidence of the 
country south, and imagine this whole mass converted by earth- 
quake pulsations of the breadth which such undulations have, 
into a series of stupendous and rapid-moving waves of transla- 
tion, helped on by the still more rapid flexures of the floor over 
which they move, and then advert to the shattering and loosen- 
ing power of the tremendous jar of the earthquake, we shall have 
an agent adequate in every way to produce the results we see, to 
float the northern ice from its moorings, to rip off, assisted with 
its aid, the outcrops of the hardest strata, to grind up and strew 
wide their fragments, to scour down the whole rocky floor, and, 
oathering energy with resistance, to sweep up the slopes and over 
the highest mountains.’’ 


Because of the prominence of their author, Rogers’s 
views exerted some influence and seemingly received 
support from England through the elaborate mathematic 
discussions of Whewell (1848), who considered the drift 


Gregory—Progress in Interpretation of Land Forms. 119 


as “‘irresistible proof of paroxysmal action,’’ and Hop- 
kins (1852), who contended for ‘‘currents produced by 
repeated elevatory movements. ’’ 

After his arrival in America (1846), Agassiz’s influ- 
ence was felt, and his paper on the erratic phenomena 
about Lake Superior (1850),*° in which he called upon 
the advocates of water-borne ice to point out the barrier 
which caused the current to subside, produced a salu- 
tary effect; yet Desor (1852)*° states that in the region 
deseribed by Agassiz ‘‘the assumption [of a general ice 
cap] is no longer admissible,’’ and that the bowlders on 
Long Island ‘‘were transported on ice rafts along the sea 
shore and stranded on the ridges and eminences which 
were then shoals along the coast.’’ Twenty years of 
discussion were insufficient to establish the glacial theory 
either in Europe or America. The consensus of opinion 
among the more advanced thinkers in 1860 is expressed 
by Dana :** 


‘“In view of the whole subject, it appears reasonable to con- 
clude that the Glacier theory affords the best and fullest 
explanation of the phenomena over the general surface of the 
continents, and encounters the fewest difficulties. But icebergs 
have aided beyond doubt in producing the results along the 
borders of the continents, across ocean-channels like the German 
Ocean and the Baltic, and possibly over great lakes like those of 
North America. Long Island Sound is so narrow that a glacier 
may have stretched across it.’’ 


Papers in the Journal of 1860-70 show a prevailing 
belief in icebergs, but the evidence for land ice was 
accumulating as the deposits became better known, and 
in 1871 field workers speak in unmistakable tones :*6 


‘*Tt is still a mooted question in American geology whether the 
events of the Glacial era were due to glaciers or icebergs. ... 
American geologists are still divided in opinion, and some of the 
most eminent have pronounced in favor of icebergs. 

Sinee, then, icebergs cannot pick up masses tons in weight 
from the bottom of a sea, or give a general movement southward 
to the loose-material of the surface; neither can produce the 
abrasion observed over the rocks under its various conditions; 
and inasmuch as all direct evidence of the submergence of the 
land required for an iceberg sea over New England fails, the 
conclusion appears inevitable that icebergs had nothing to do 
with the drift of the New Haven region, in the Connecticut 
valley; and, therefore, that the Glacial era in central New Eng- 
land was a Glacier era.’’ 


120 Gregory—Progress wm Interpretation of Land Forms. 


Matthew (1871)*® reached the same conclusion for the 
Lower Provinces of Canada. In spite of the increasing 
clarity of the evidence, the battle for the glacial theory 
was not yet won. The remaining opponents though few 
in number were distinguished in attainments. Dawson 
clung to the outworn doctrine until his death in 1899. 

An interesting feature of the history of glacial theories 
is the calculation by Maclaren (1842)*°° that the amount 
of water abstracted from the seas to form the hypo- 
thetical ice sheet would lower the ocean-level 350 feet— 
an early form of the glacial control penal (see 
Dalye=). 


Extent of Glacial Drift. 


By the middle of the 19th century, it was recognized 
that the ‘‘drift,’’ whatever its origin, was’ not of world- 
wide extent. In America its characteristic features were 
found best developed north of latitude 40 degrees; in 
Kurope, the Alps, the Scottish Highlands, and Seandi- 
navia were recognized as type areas. The limits were 
unassigned, partly because the field had not been sur- 
veyed, but largely because criteria for the recognition of 
drift had not been established. The well-known hillocks 
and ridges of ‘‘diluvium”’ and ‘‘alluvium’’ and ‘‘drift’’ 
of New Jersey and Ohio, and the mounds of the Missouri 
Cotou elaborately described by Catlin (1840)°? bore 
little resemblance to the walls of unsorted rock which 
stand as moraines bordering Alpine glaciers. The 
Orange sand of Mississippi was included in the drift by 
Hileard (1866),>? and the gravels at Philadelphia by 
Hall (1876).24 Stevens (1873)*> described trains of 
glacial erratics at Richmond, Virginia, and Wm. B. 
Rogers (1876)°* accounts for certain deposits in the Poto- 
mac, James, and Roanoke rivers by the presence of 
Pleistocene ice tongues or swollen glacial rivers, and 
remarks: ‘‘It is highly probable that glacial action had 
much to do with the original accumulation of the rocky 
debris on the flanks of the Blue Ridge, and in the Appa- 
lachian valleys beyond.’’ Kerr (1881)°" referred the 
ancient erosion surface of the Piedmont belt in North 
Carolina to glacial denudation, De la Beche compared 
the drift of Jamaica with that of New England, and 
Agassiz interpreted soils of Brazil as glacial. 


Gregory—Progress in Interpretation of Land Forms. 121 


The first detailed description and unequivocal inter- 
pretation of either terminal or recessional moraines is 
from the pen of Gilbert (1871),°* geologist of the Ohio 
Survey. In discussing the former outlet of Lake Erie 
through the Fort Wayne channel, Gilbert writes: 


““The page of history recorded in these phenomena is by no 
means ambiguous. The ridges, or, more properly, the ridge 
which determines the courses of the St. Joseph and St. Marys 
rivers is a buried terminal moraine of the glacier that moved 
southwestward through the Maumee valley. The overlying Erie 
Clay covers it from sight, but it is shadowed forth on the surface 
of that deposit, as the ground is pictured through a deep and 
even canopy of snow. Its irregularly curved outline. accords 
intimately with the configuration of the valley, and with the 
direction of the ice markings; its concavity is turned toward 
the source of motion; its greatest convexity is along the lne of 
least resistance. 

South of the St. Marys river are other and numerous moraines 
accompanied by glacial strie. Their character and courses 
have not yet been studied; but their presence carries the mind 
back to an epoch of the cold period, when the margin of the ice- 
field was farther south, and the glacier of the Maumee valley was 
merged in the general mass. As the mantle of ice grew shorter— 
and, in fact, at every stage of its existence—its margin must have 
been variously notched and lobed in conformity with the contour 
of the country, the higher lands being first laid bare by the 
encroaching secular summer. Early in the history of this 
encroachment the glacier of the Maumee valley constituted one of 
these lobes, and has recorded its form in the two moraines that 
I have described.’’ 


Three years after the recognition of moraines in the 
Maumee valley, Chamberlin (1874)°? showed that the 
seemingly. disorganized mounds and basins and ridges 
known as the Kettle range of Wisconsin is the terminal 
moraine of the Green Bay glacier. At an earlier date 
(1864) Whittlesey interpreted the kettles of the Wis- 
consin moraine as evidence of ice blocks from a melting 
elacier and presented a map showing the ‘‘southern 
limit of boulders and coarse drift.’’ In 1876 attention 
was called to the terminal moraine of New England by G. 
Frederick Wright, who assigns the honor of discovery to 
Clarence King. 

With the observations of Gilbert, Chamberlin, and 
King in mind, the terminal moraine was traced by 
various workers across the United States and into 


122 Gregory—Progress mm Interpretation of Land Forms. 


Canada and the extent of glacial cover revealed. Fol- 
lowing 1875 the pages of the Journal contain many con- 
tributions dealing with the origin and structure of 
moraines, eskers, kames, and drumlins. Before 1890 
twenty-eight papers on the glacial phenomena of the Hrie 
and Ohio basin alone had appeared. By 1900 substantial 
agreement had been reached regarding the significant 
features of the drift, the outline history of the Great 
Lakes had been written, and the way had been paved for 
stratigraphic studies of the Pleistocene, which bulk large 
in the pages of the Journal for the last two decades. 


Epochs of Glaciation. 


For a decade following the general acceptance of the 
glacial origin of ‘‘diluvium,’’ the deposits were embraced 
as ‘‘drift’’ and treated as the products of one long period 
of glacial activity, and throughout the controversy of 
iceberg and glacier the unity of the glacial period was 
unquestioned. Beds of peat and fossiliferous lacustrine 
deposits in Switzerland, England, and in America and 
the recognition of an ‘‘upper’’ and a ‘‘lower’’ diluvium 
by Scandinavian geologists suggested two epochs, and as 
the examples of such deposits increased in number and 
it became evident that the plant fossils represented forms 
demanding a genial climate and that the phenomena 
were seen in many countries, the belief grew that minor 
fluctuations or gradual recession of an ice sheet were 
inadequate to account for the phenomena observed. 

It is natural that this problem should have found its 
solution in America, where the Pleistocene is admirably 
displayed, and where the State and Federal surveys were 
actively engaged in areal mapping. In 1883 Chamber- 
lin®’ presented his views under the bold title, ‘‘ Prelim- 
inary Paper on the Terminal Moraine of the Second 
Glacial Epoch,’’ and the existence of deposits of two or 
more ice sheets and the features of interglacial periods 
were substantially established by the interesting debate 
in the Journal led by Chamberlin, Wright, Upham and 
Dana.*! Contributions since 1895 have been concerned 
with the degree rather than the fact of complexity, and 
continued study has resulted in the general recognition 
of five glacial stages in North America and four in 
Kurope. 


Gregory—Progress in Interpretation of Land Forms. 123 


The Loess as a Glacial Deposit. 


A curious side-product of the study of glaciation in 
North America is the controversy over the origin of loess. 
The interest aroused is indicated by scores of papers in 
American periodicals and State reports of the last quar- 
ter of the 19th century—papers which bear the names of 
prominent geologists. 

The ‘‘loess’’ in the valley of the Rhine had long been 
known, but the subject assumed prominence by the pub- 
heation in 1866 of Pumpelly’s Travels in China.®? Wide- 
spread deposits 200 to 1,000 feet thick were described as 
very fine-grained yellowish earth of distinctive structure 
without stratification but penetrated by innumerable 
tubes and containing land or fresh-water shells. Pum- 
pelly considered these deposits lacustrine, a view which 
found general acceptance though combated by Kingsmill 
(1871),°° who argued for marine deposition. Baron Von 
Richthofen’s classic on China, which appeared in 1877, 
amplifies the observations of Pumpelly and marshals the 
evidence to support the hypothesis that the loess is wind- 
laid both on dry land and within ancient salt lakes. The 
conclusions of Von Richthofen were adopted by Pumpellv 
whose knowledge of the Chinese deposits, supplemented 
by studies in Missouri, of which State he was director of 
the Geological Survey in 1872-73, placed him in position 
to form a correct judgment. He says:*+ 


“Recognizing from personal observation the full identity of 
character of the loess of northern China, Europe and the Mis- 
souri Valley, I am obliged to reject my own explanation of the 
origin of the Chinese deposits, and to believe with Richthofen 
that the true loess, wherever it occurs, is a sub-aerial deposit, 
formed in a dry central region, and that it owes its structure to 
the formative influence of a steppe vegetation. 

The one weak point of Richthofen’s theory is in the evident 
inadequacy of the current disintegration as a source of material. 
When we consider the immense area covered by loess to depths 
varying from 50 to 2,000 feet, and the fact that this is only the 
very finest portion of the product of rock-destruction, and again 
that the accumulation represents only a very short period of 
time, geologically speaking, surely we must seek a more fertile 
source of supply than is furnished by the current decomposition 
of rock surface. 

It seems to me that there are two important sources: I. The 
silt brought by rivers, many of them fed by the products of 
glacial attrition flowing from the mountains into the central 


124 Gregory—Progress in Interpretation of Land Forms. 


region. Where the streams sink away, or where the lakes which 
receive them have dried up, the finer products of the erosion 
of a large territory are left to be removed in dust storms. 

II. The second ... source is the residuary products of a 
secular disintegration.”’ iy 


The evidence presented by Pumpelly for the eolian 
origin of loess—structure, texture, composition, fossil 
content and topographic position—is complete, and to him 
belongs the credit for the correct interpretation of the 
Mississippi valley deposits. Unfortunately his contribu- 
tion came at a time when the geologists of the central 
States were intent on tracing the paths and explaining 
the work of Pleistocene glaciers, and the belief was 
strong that loess was some phase of glacial work. Its 
position at the border of the Jowan drift so obviously 
suggests a genetic relation that the fossil evidence of 
steppe climate suggested by Binney in 1848° was mini- 
mized. Students of Pleistocene geology in Minnesota, 
Iowa, Nebraska, Missouri, although less vigorous in 
expression, were substantially in agreement with Hilgard 
(1879).°° ‘*The sum total of anomalous conditions 
required to sustain the eolian hypothesis partakes 
strongly of the marvellous.’’ The last edition of Dana’s 
Manual, 1894, and of LeConte’s Geology, 1896, the two 
most widely used text books of their time, oppose the 
eolian theory, and Chamberlin, in 1897, states: ‘‘the 
aqueous hypothesis seems best supported so far as con- 
cerns the deposits of the Mississippi Valley and western 
Europe’’ (p. 795). Shimek, in papers published since 
1896 has shown that aquatic and glacial conditions can 
not account for the loess fossils, and the return to the 
views of Pumpelly that the loess was deposited on land 
by the agency of wind in a region of steppe vegetation is 
now all but universal. 


Glacial Sculpture. 


Within the present generation sculpture by glaciers has 
received much attention and has involved a reconsidera- 
tion of the ability of ice to erode which in turn involves 
a crystallization of views of the mechanics of moving ice. 
The evidence for glacier erosion has remained largely 
physiographic and rests on a study of land forms. In 
fact, the inadequacy of structural features or of river 


\ 220% 
Gregory—Progress in Interpretation of Land Forms. 125 


corrasion to account for flat-floored, steep-walled gorges, 
hanging valleys, and many lake basins, rather than a 
knowledge of the mechanics of ice has led to the present 
fairly general belief that glaciers are powerful agents of 
rock sculpture. The details of the process are not yet 
understood. 

Krosion by glaciers enters the arena of active discus- 
sion in 1862-63. The possibility had been suggested by 
Esmark (1827) and by Dana (1849) in the description of 
fiords and by Hind (1855) with reference to the origin 
of the Great Lakes. It appears full-fledged in Ramsay’s 
classic, which was published simultaneously in Kngland 
and in America.** The argument runs as follows: 
There is a close association of ancient glaciers and lakes 
especially in mountains; glaciers are amply able to 
erode; evidences of faulting, special subsidence, river 
erosion, and marine erosion are absent from the lake 
basins of Switzerland and Great Britain. To quote 
Ramsay: 


‘Tt required a solid body grinding steadily and powerfully in 
direct and heavy contact with and across the rocks to scoop out 
deep hollows, the situations of which might either be determined 
by unequal hardness of the rocks, by extra weight of ice in 
special places, or by accidental circumstances, the clue to which 
is lost from our inability perfectly to reconstruct the original 
forms of the glaciers.’ 

‘*T believe with the Italian geologists, that all that the glaciers 
as a whole effected was only shghtly to deepen these valleys and 
materially to modify their general outlines, and, further (a the- 
ory I am alone responsible for), to deepen them in parts more 
considerably when, from various causes, the grinding power of 
the ice was unusually powerful, especially where, as in the low- 
lands of Switzerland, the Miocene strata are comparatively soft.’’ 


Whittlesey (1864)°° considered that the rock-bound 
lakes and narrow bays near Lake Superior were partly 
excavated by ice. LeConte (1875)*° records some sig- 
nificant observations in a pioneer paper on glacier 
erosion which has not received adequate recognition. 
He says: 


‘*. . . [am eonvineed that a glacier, by its enormous pressure 


and resistless onward movement, is constantly breaking off large 
blocks from its bed and bounding walls. Its erosion is not only a 
erinding and scoring, but also a crushing and breaking. It 
makes by its erosion not only rock-meal, but also large rock- 


126 Gregory—Progress in Interpretation of Land Forms. 


chips. . . . Its erosion is a constant process of alternate rough 
hewing and planing. 

If Yosemite were unique, we might suppose that it was 
formed by violent cataclysms; but Yosemite is not unique in 
form and therefore probably not in origin. There are many 
Yosemites. It is more philosophical to account for them by the 
regular operation of known causes. I must believe that all these 
deep perpendicular slots have been sawn out by the action of gla- 
ciers ; the peculiar verticaltty of the walls haying been determined 


by the perpendicular cleavage structure.’’ . . . A lake in Bloody 
Canyon ‘‘is a pure rock basin scooped out by the glacier at this 
place. .. . These ridges [separating Hope, Faith, and Charity 


valleys] are in fact the lips of consecutive lake basins scooped 
out by ice. 

. . . Water tends to form deep V-shaped canons, while ice pro- 
duees .broad valleys with lakes and meadows. . . . I know not 
how general these distinctions may be, but certainly the Coast 
range of this State is characterized by rounded summits and 
ridges, and deep V-shaped canons, while the high Sierras are 
characterized on the contrary by sharp, spire-like, comb-like 
summits, and broad valleys; and this difference 1-am convinced 
is due in part at least to the action of water on the one hand, 
and of ice on the other.’’ 


King (1878) assigned to glacial erosion a command- 
ing position in mountain sculpture. In regard to the 
Uintas, he says: ? 7 


‘‘Glacial erosion has cut almost vertically down through the 
beds carving immense amphitheatres with basin bottoms con- 
taining numerous Alpine lakes. . . . Post-glacial erosion has done 
an absolutely trivial work. There is not a particle of direct 
evidence, so far as I can see, to warrant the belief that these 
U-shaped canons were given their peculiar form by other means 
than the actual ploughing erosion of glaciers. .. .’’ 


These contributions from the Cordilleras corroborat- 
ing the conclusions of Ramsay (1862), Tyndall (1862), 
Jukes (1862), Hector (1863), Logan (1863), Close (1870), 
and James Geikie (1875), made little impression. The 
views of Lyell (1833), Ball (1863), J. W. Dawson (1864), 
Falconer (1864), Studer (1864), Murchison (1864, 1870), 
Ruskin (1865), Rutimeyer (1869), Whymper (1871), 
Bonney (1873), Pfaff (1874), Gurlt (1874), Judd (1876), 
prevailed, and the conclusions of Davis in 1882" fairly 
expressed the prevailing belief in Europe and in 
America: 


Gregory—Progress in Interpretation of Land Forms, 127 


‘“‘The amount of glacial erosion in the central districts has 
been very considerable, but not greatly in excess of pre-glacial 
soils and old talus and alluvial deposits. Most of the solid rock 
that was carried away came from ledges rather than from val- 
leys; and glaciers had in general a smoothing rather than a 
roughening effect. In the outer areas on which the ice advanced 
it only rubbed down the projecting points; here it acted more 
frequently as a depositing than as an eroding agent.’’ 


During the past quarter-century the cleavage in the 
ranks of geologists, brought about by Ramsay’s classic 
paper, has remained. Fairchild and others in America, 
Heim, Bonney, and Garwood in Hurope argue for insig- 
nificant erosion by glaciers; and Gannet, Davis, Gilbert, 
Tarr in America followed by Austrian workers present 
evidence for erosion on a gigantic scale. A perusal of 
the voluminous literature in the Journal and elsewhere 
shows that the difference of opinion is in part one of 
terms, the amount of erosion rather than the fact of 
erosion; it also arises from failure to differentiate the 
work of mountain glaciers and continental ice sheets, of 
Pleistocene glaciers and their present diminished repre- 
sentatives. The irrelevant contribution of physicists has 
also made for confusion. 

It is interesting to note that the criteria for erosion 
of valleys by glaciers has long been established and 
by workers in different countries. Ramsay (1862) in 
England outlined the problem and presented generalized 
evidence. Hector (1863) in New Zealand pointed out 
the significance of discordant drainage, the ‘‘hanging 
valleys’’ of Gilbert. The U-form, the broad lake-dotted 
floor, and the presence of cirques and the process of 
plucking were probably first described by LeConte 
(1873) in America. The truncation of valley spurs by 
glaciers pointed out by Studer in the Kerguelen Islands 
(1878) was used by Chamberlin (1883) as evidence of 
glacial scouring. 


CONCLUSION. 


During the past century many principles of land 
sculpture have emerged from the fog of intellectual 
speculation and unorganized observation and taken their 
place among generally accepted truths. Many ‘of them 
are no longer subjects of controversy. Erosion has 


128 Gregory—Progress in Interpretation of Land Forms. 


found its place as a major geologic agent and has given 
a new conception of natural scenery. Lofty mountains 
are no longer ‘‘ancient as the sun,’’ they are youthful 
features in process of dissection; valleys and canyons 
are the work of streams and glaciers; fiords are erosion 
forms; waterfalls and lakes are features in process of 
elimination; many plains and plateaus owe their form 
and position to long-continued denudation. Modern 
landscapes are no longer viewed as original features or 
the product of a single agent acting at a particular time, 
but as ephemeral forms which owe their present appear- 
ance to their age and the particular forces at work upon 
them as well as to their original structure. 

It is interesting to note the halting steps leading to the 
present viewpoint, to find that decades elapsed between 
the formulation of a theory or the recording of signifi- 
cant facts and their final acceptance or rejection, and to 
realize that the organization of principles and observa- 
tions into a science of physiography has been the work 
of the present generation. Progress has been condi- 
tioned by a number of factors besides the intellectual 
ability of individual workers. Pa. 

The influence of locality is plainly seen. Convincing 
evidence of river erosion was obtained in central France, 
the Pacific Islands, and the Colorado Plateau—regions 
in which other causes were easily eliminated. Sculpture 
by glaciers passed beyond the theoretical stage when the 
simple forms of the Sierras and New Zealand Alps were 
described. The origin of loess was first discerned in a 
region where glacial phenomena did not obscure the 
vision. The complexity of the Glacial period asserted by 
geologists of the Middle West was denied by eastern ~ 
students. The work of waves on the English coast 
impressed British geologists to such an extent that plains 
of denudation and inland valleys were ascribed to 
ocean work. 

In the establishment of principles, the friendly inter- 
change of ideas has yielded large returns. Many of the 
fundamental conceptions of earth sculpture have come 
from groups of men so situated as to facilitate criticism. 
It is impossible, even if desirable, to award individual 
credit to Venetz, Charpentier, and Agassiz in the formu- 
lation of the glacial theory; and the close association of 
Agassiz and Dana in New England and of Chamberlin 


Gregory—Progress in Interpretation of Land Forms, 129 


and Irving in Wisconsin was undoubtedly helpful in 
establishing the theory of continental glaciation. From 
the intimate companionship in field and laboratory of 
Hutton, Playfair and Hope, arose the profound influence 
of the Edinburgh school, and the sympathetic cooperation 
of Powell, Gilbert, and Dutton has given to the world its 
classics in the genetic study of land forms. 

The influence of ideas has been closely associated with 
clarity, conciseness, and attractiveness of presentation. 
Hutton is known through Playfair, Agassiz’s contribu- 
tions to glacial geology are known to every student, while 
Venetz, Charpentier, and Hugi are only names. Cuvier’s 
discourses on dynamical geology were reprinted and 
translated into English and German, but Lamarck’s 
‘‘Hydrogéologie’’ is known only to book collectors. The 
verbose works of Guettard, although carrying the same 
message as Playfair’s ‘‘Illustrations’’ and Desmarest’s 
‘‘Memoirs,’’ are practically unknown, as is also Horace 
H. Hayden’s treatise (1821) on the drift of eastern 
North America. It has been well said that the world- 
wide influence of American physiographic teaching is due 
in no small part to the masterly presentations of Gilbert 
and Davis. 

It is surprising to note the delays, the backward steps, 
and the duplication of effort resulting from lack of 
familiarity with the work of the pioneers. Sabine says 
in 1864 :*8 


““Tt often happens, not unnaturally, that those who are most 
occupied with the questions of the day in an advancing science 
retain but an imperfect recollection of the obhgations due 
to those who laid the first foundations of our subsequent 
knowledge.’’ 


The product of intellectual effort appears to be con- 
ditroned by time of planting and character of soil as well 
as by quantity of seed. For example: Erosion by 
rivers was as clearly shown by Desmarest as by Dana and 
Newberry 50 years later. Criteria for the recognition of 
ancient fluviatile deposits were established by James 
Deane in 1847 in a study of the Connecticut Valley 
Triassic. Agassiz’s proof that ice is an essential factor 
in the formation of till is substantially a duplication of 
Dobson’s observations (1826). 

The volumes of the Journal with their very large num- 


Am. Jour. Scr.—FourtTa SERIES, VoL. XLVI, No. 271.—Jtty, 1918. 
5 


130 Gregory—Progress im Interpretation of Land Forms. 


ber of articles and reviews dealing with geology show 
that the interpretation of land forms as products of 
subaérial erosion began in France and French Switzer- 
land during the later part of the 18th century as a phase 
of the intellectual emancipation following the Revolution. 
Scotland and England assumed the leadership for the 
first half of the 19th century, and the first 100 volumes of 
the Journal show the profound influence of English and 
French teaching. In America, independent thinking, 
early exercised by the few, became general with the 
establishment of the Federal survey, the increase in uni- 
versity departments, geological societies and periodi- 
cals, and has given to Americans the responsibilities of 


teachers. 
BIBLIOGRAPHY. 


Wilson, J. W., Bursting of lakes through mountains, this Journal, 3, 
253, 1821. 

2 Whitney, J. D., Progress of the Geological Survey of California, this 
Journal, 38, 263-264, 1864. 

° Playfair, John, Illustrations of the Huttonian theory of the earth, Edin- 
burgh, 1802. ; 

*Kain, J. H., Remarks on the mineralogy and geology of northwestern 
Virginia and eastern Tennessee, this Journal, 1, 60-67, 1819. 

> Hitchcock, Edward, Geology, ete., of regions contiguous to the Connect- 
icut, this Journal, 7, 1-30, 1824. 

$6 Buckland, Wm., Reliquie diluviane, this Journal, 8, 150, 317, 1824. 

7 Phillips, John, Geology of Yorkshire, this Journal, 21, 17-20, 1832. 

8 Scrope, G. P., Excavation of valleys, Geol. Soc., London, No. 14, 1850. 

° Hayes, G. H., Remarks on geology and topography of western New 
York, this Journal, 35, 88-91, 1839. 

*? Seventh Meeting of the British Association for the Advancement of 
Science, this Journal, 33, 288, 1838. 

1 Darwin, Charles, Geological observations on the voleanic islands and 
parts of South America, etc., second part of the Voyage of the ‘‘Beagle,’’ 
during 1832-1836. London, 1844. 

Hildreth, S. P., Observations, etc., valley of the Ohio, this Journal, 29, 
1-148, 1836. 

18 Geddes, James, Observations on the geological features of the south 
side of Ontario valley, this Journal, 11, 213-218, 1826. 

14 Conrad, T. A., Notes on American geology, this Journal, 35, 287-251, 
1839. 

* Warren, G. K., Preliminary report of explorations in Nebraska and 
Dakota, this Journal, 27, 380, 1859. 

16 Lesley, J. P., Observations on the Appalachian region of southern 
Virginia, this Journal, 34, review, 413-415, 1862. 

** Hitchcock, Edward, First anniversary address before the Association 
of American Geologists, this Journal, 41, 232-275, 1841. 

* Dana, J. D., On denudation in the Pacific, this Journal, 9, 48-62, 1850. 

———————., On the degradation of the rocks of New South Wales and 
formation of valleys, this Journal, 9, 289-294, 1850. 

* Hubbard, O. P., On the condition of trap dikes in New Hampshire an 
evidence and measure of erosion, this Journal, 9, 158-171, 1850. 

*° Hayden, F. V., Some remarks in regard to the period of elevation of 
the Rocky Mountains, this Journal, 33, 305-313, 1862. 


Gregory—Progress in Interpretation of Land Forms. 131 


"1 Newberry, J. S., Colorado River of the West, this Journal, 33, review, 
387-403, 1862. 

= Jukes, J. B., Address to the Geological Section of the British Associa- 
tion at Cambridge, Quart. Jour. Geol. Soc., 18, 1862, this Journal, 34, 439, 
1862. 

* Powell, J. W., Exploration of the Colorado River of the West, 1875. 
For Powell’s preliminary article see this Journal, 5, 456-465, 1873. 

“McGee, W. J., Three formations of the Middle Atlantic slope, this 
Journal, 35, 120, 328, 367, 448, 1888. 

*“ Davis, W. M., Topographic development of the Triassic formation of 
the Connecticut Valley, this Journal, 37, 423-434, 1889. 

7° Percival, J. G., Geology of Connecticut, 1842. 

* Kerr, W. C., Origin of some new points in the topography of North 
Carolina, this Journal, 21, 216-219, 1881. 

** McGee, W. J., The classification of geographic forms by genesis, Nat. 
Geogr. Mag., 1, 27-36, 1888. 

“Davis, W. M., The rivers and valleys of Pennsylvania, Nat. Geogr. 
Mag., 1, 183-253, 1889. 

——_—_—., The rivers of northern New Jersey with notes on the classi- 
fication of rivers in general, ibid., 2, 81-110, 1890. 

* Silliman, Benjamin, Notice of Horace H. Hayden’s geological essays, 
this Journal, 3, 49, 1821. 

* Cornelius, Elias, Account of a singular position of a granite rock, this 
Journal, 2, 200-201, 1820. 

= Finch, John, On the Celtic antiquities of America, this Journal, 7, 149- 
161, 1824. 

** Finch, John, Geological essay on the Tertiary formations in America, 
this Journal, 7, 31-43, 1824. 

** Conybeare and Phillips, Outlines of the geology of England and Wales, 
this Journal, 7, 210, 211, 1824. 

** Hayden, Horace H., Geological essays, 1-412, 1821, this Journal, 3, 
47-57, 1821. 

*° Jackson, C. T., Reports on the geology of the State of Maine, and on 
the public lands belonging to Maine and Massachusetts, this Journal, 36, 
153, 1839. 

* Gibson, J. B., Remarks on the geology of the lakes and the valley of 
the Mississippi, this Journal, 29, 201-213, 1836. 

** Phillips, John, Geology of Yorkshire, this Journal, 21, 14-15, 1832. 

“ Granger, Ebenezer, Notice of a curious fluted rock at Sandusky Bay, 
Ohio, this Journal, 6, 180, 1823. 

* Dobson, Peter, Remarks on bowlders, this Journal, 10, 217-218, 1826. 

** Murchison, R. I., Address at anniversary meeting of the Geological 
Society of London, this Journal, 43, 200-201, 1842. 

= Buckland, W., On the evidence of glaciers in Scotland and the north 
of England, Proce. London Geol. Soce., 3, 1841. 

* Third annual meeting of the Association of American Geologists and 
Naturalists, this Journal, 43, 154, 1842; Abstract of proceedings of the 
fourth session of the Association of American Geologists and Naturalists, 
ibid., 45, 321, 1843. 

* Rogers, H. D., Address delivered before Association of American Geol- 
ogists and Naturalists, this Journal, 47, 275, 1844. 

* Agassiz, Louis, The erratic phenomena about Lake Superior, this 
Journal, 10, 83-101, 1850. 

*Desor, E., On the drift of Lake Superior, this Journal, 13, 93-109, 
1852; Post-Pliocene of the southern States, etc., 14, 49-59, 1852. 

* Dana, J. D., Manual of geology, 546, Philadelphia, 1863. 

* Dana, J. D., on the Quaternary, or post-Tertiary of the New Haven 
region, this Journal, 1, 1-5, 1871. 

* Matthew, G. F., Surface geology of New Brunswick, this Journal, 2, 
371-372, 1871. 


132 Gregory—Progress wm Interpretation of Land Forms. 


°° Maclaren, Charles, The glacial theory of Prof. Agassiz, this Journal, 
42, 365, 1842. 

1 Daly, R. A., Problems of the Pacific Islands, this Journal, 41, 153-186, 
1916. 

Catlin, George, Account of a journey to the Coteau des Prairies, this 
Journal, 38, 138-146, 1840. 

 Hilgard, E. W., Remarks on the drift of the western and southern States 
and its relation to the glacier and ice-berg theories, this Journal, 42, 343- 
347, 1866. 

*4 Hall, C. E., Glacial phenomena along the Kittatinny or Blue Mountain, 
Pennsylvania, this Journal, 11, review, 233, 1876. 

> Stevens, R. P., On glaciers of the glacial era in Virginia, this Journal, 
6, 371-373, 1873. 

°° Rogers, W. B., On the gravel and cobble-stone deposits of Virginia and 
the Middle States, Proc. Boston Soc. Nat. Hist., 18, 1875; this Journal, 
11, 60-61, 1876. 

*™ Kerr, W. C., Origin of some new points in the topography of North 
Carolina, this Journal, 21, 216-219, 1881. 

*§ Gilbert, G. K., On certain glacial and post-glacial phenomena of the 
Maumee valley, this Journal, 1, 339-345, 1871. 

°° Chamberlin, T. C., On the geology of eastern Wisconsin, Geol. of 
Wisconsin, 2, 1877; this Journal, 15, 61, 406, 1878. 

* Chamberlin, T. C., Preliminary paper on the terminal moraine of the 
second glacial epoch, U. 8. Geol. Survey, Third Ann. Rept., 291-402, 1883. 

“ Wright, G. F., Unity of the glacial epoch, this Journal, 44, 351-373, 
1892. 

Upham, Warren, The diversity of the glacial drift along its boundary, 
ibid., 47, 358-365, 1894. 

Wright, G. F., Theory of an interglacial submergence in England, ibid., 
43, 1-8, 1892. | 

Chamberlin, T. C., Diversity of the glacial period, ibid., 45, 171-200, 
1893. 

Dana, J. D., On eu England and the upper Mississippi basin in the 
glacial period, ibid., 46, 327-330, 1893. 

Wright, G. F., Continuity of the glacial period, ibid., 47, 161-187, 1894. 

Chamberlin, T. C. and Leverett, F., Further studies of the drainage 
features of the upper Ohio basin, ibid., 47, 247-282, 1894. 

“ Pumpelly, Raphael, Geological researches in China, Japan, and Mon- 
golia, Smithsonian Contributions, No. 202, 1866. 

* Kingsmill, T. W., The probable origin of ‘‘loess’’ in North China 
and eastern Asia, Quart. Jour. Geol. Soc., 27, No. 108, 1871. 

**Pumpelly, Raphael, The relation of secular rock-disintegration to loess, 
glacial drift and rock basins, this Journal, 17, 135, 1879. 

* Binney, A., Some geologic features at Natchez on the Mississippi River, 
Proce. Boston Soc. Nat. Hist., 2, 126-130, 1848. 

* Hilgard, EH. W., The loess of Mississippi Valley, and the eolian hypoth- 
esis, this Journal, 18, 106-112, 1879. 

* Chamberlin, T. C., Supplementary hypothesis respecting the origin of 
the loess of the Mississippi Valley, Jour. Geol., 5, 795-802, 1897. 

*® Ramsay, A. C., On the glacial origin of certain lakes in Switzerland, 
the Black Forest, Great Britain, Sweden, North America, and elsewhere, 
Quart. Jour. Geol. Soc., 1862; this Journal, 35, 324-345, 1863. Preliminary 
statements of this theory appeared in 1859 and 1860. 

© Whittlesey, Charles, Smithsonian Contributions, No. 197, 1864. 

 LeConte, Joseph, On some of the ancient glaciers of the Sierras, this 
Journal, 5, 325-342, 1873, 10, 126-139, 1875. 

™ King, Clarence, U. S. Geol. Expl. 40th Par., 1, 459-529, 1878. 

@ Davis, W. M., Glacial erosion, Proce. Boston Soc. Nat. Hist., 22, 58, 
1882. 

“Sabine, Sir Edward, Address of the president of the Hoye Society, 
this Journal, of, L108, 1864. 


Barrell—Growth of Knowledge of Earth Structure. 135 


Arr. 1V.—Grouoey continued; The Growth of Knowledge 
of Earth Structure; by JosEPH BaRRELt. 


INTRODUCTION. 
The Intellectual Viewpoint m 1818. 


In 1818, the year of the founding of this Journal, the 
natural sciences were still in their infancy in Kurope. 
Geology was still subordinate to mineralogy, was hardly 
recognized as a distinct science, and consisted in httle 
more than a description of the character and distribution 
of minerals and rocks. America was remote from the 
Old World centers of learning. The energy of the young 
nation was absorbed in its own expansion, and but a few 
of those who by aptitude were fitted to increase scientific 
knowledge were even conscious of the existence of such a 
field of endeavor. Under these circumstances the edu- 
eative field open to a journal of science in the United 
States was an almost virgin soil. Original contributions 
could most readily be based upon the natural history of 
the New World, and the founder of the Journal showed 
insight appreciative of the situation in stating in the 
‘‘Plan of the Work’’ in the introduction to the first vol- 
ume that ‘‘It will be a leading object to illustrate Amert- 
can Natura History, and especially our MinrRaLocy 
and GEOLOGY. 

At this time educated people were still satisfied that 
the whole knowledge of the origin and development of 
the earth so far as man could or should know it was 
embraced in the Book of Genesis. They were inclined to 
look with misgiving at attempts to directly interrogate the 
earth as to its history. Philosophers such as Descartes 
and Liebnitz, the cosmogonists de Maillet and Buffon 
had been less instrumental in developing science than in 
fitting a few facts and many speculations to their systems 
of philosophy. By the opening of the nineteenth cen- 
tury, however, men of learning were coming to appre- 
ciate that the way to advance science was to experiment 
and observe, to collect facts and discourage unfounded 
speculation. Silliman’s insight into the needs of geologic 
science is shown in the following quotation (1, pp. 6, 
Tersls )-: 


134 Barrell—Growth of Knowledge of Earth Structure. 


‘‘Our geology, also, presents a most interesting field of inquiry. 
A grand outline has recently been drawn by Mr. Maclure, with 
a masterly hand, and with a vast extent of personal observation 
and labour: but to fill up the detail, both observation and labour 
still more extensive are demanded; nor can the object be 
effected, till more good geologists are formed, and distributed 
over our extensive territory. 

To account for the formation and changes of our globe, by 
excursions of the imagination, often splendid and imposing, but 
usually visionary, and almost always baseless, was, till within 
half a century, the business of geological speculations; but this 
research has now assumed a more sober character; the science 
of geology has been reared upon numerous and accurate obser- 
vations of facts; and standing thus upon the basis of induc- 
tion, it is entitled to a rank among those sciences which Lord 
Bacon’s Philosophy has contributed to create. Geological 
researches are now prosecuted by actually exploring the struc- 
ture and arrangement of districts, countries, and continents. 
The obliquity of the strata of most rocks, causing their edges 
to project in many places above the surface; their exposure, in 
other instances on the sides or tops of hills and mountains; 
or, in consequence of the intersection of their strata, by roads, 
canals, and river-courses, or by the wearing of the ocean; or 
their direct perforation, by the shafts of mines; all these causes, 
and others, afford extensive means of reading the interior 
structure of the globe. 

The outlines of American geology appear to be particularly 
erand, simple, and instructive; and a knowledge of the import- 
ant facts, and general principles of this science, is of vast prac- 
tical use, as regards the interests of agriculture, and the research 
for useful minerals. Geological and mineralogical descriptions, 
and maps of particular states and districts, are very much 
needed in the United States; and to excite a spirit to furnish 
them will form one leading object of this Journal.’’ 


The Prolonged Influence of outgrown Ideas. 


Those interested in any branch of science should, as a 
matter of education, read the history of that special sub- 
ject. A knowledge of the stages by which the present 
development has been attained is essential to give a 
proper perspective to the literature of each period. 
Much of the existing terminology is an inheritance from 
the first attempts at nomenclature, or may rest upon 
theories long discarded. Popular notions at variance 
with advanced teaching are often the forgotten inherit- 
ance of a past generation. 


Barrell—Growth of Knowledge of Earth Structure. 135 


Gneiss, trap, and Old Red Sandstone are names which 
we owe to Werner. The ‘‘Tertiary period”’ and ‘‘drift’’ 
are relics of an early terminology. The geology of 
tourist circulars still speaks of canyons as made by ‘‘con- 
vulsions of nature.’’ Popular writers still attribute to 
geologists a belief in a molten earth covered by a thin 
erust. Within the present century the eighteenth cen- 
tury speculations of Werner and his predecessors, postu- 
lating a supposed capacity of water to seep through the 
erust into the interior of the earth, resulting in a hypo- 
thetical progressive desiccation of the surface, views long 
abandoned by most modern geologists, have been revived 
by an astronomer into a theory of ‘‘planetology.”’ 

A review of the literature of a century brings to light 
certain tendencies in the growth of science. Each decade 
has witnessed a larger accumulation of observed facts 
and a fuller classification of these fundamental data, but 
the pendulum of interpretative theory swings away from 
the path of progress, now to one side, now to the other, 
testing out the proper direction. For decades the under. 
standing of certain classes of facts may be actually retro- 
gressive. A retrospect shows that certain minds, keen 
and unfettered by a prevailing theory, have in some 
directions been in advance of their generation. But the 
judgment of the times had not sufficient basis in knowl- 
edge for the separation and acceptance of their truer 
views from the contemporaneous tangle of false inter- 
pretations. 

An interesting illustration of these statements regard- 
ing the slow settling of opinion may be cited in regard to 
the significance of the dip of the Triassic formations of 
the eastern United States. The strata of the Massachu- 
setts-Connecticut basin possess a monoclinal easterly dip 
which averages about 20 degrees to the east. Those of 
the New Jersey-Pennsylvania-Virginia basin possess a 
similar dip to the northwest. Both basins are cut by 
great faults and the dip is now accepted by practically 
all geologists as due to rotation of the crust blocks 
away from a geanticlinal axis between the two basins. 
Hdward Hitchcock, whose work from the first shows an 
interpretative quality in advance of his time, states in 
oe (6, 74) regarding the dip of the Connecticut valley 
rocks: 


136 Barrell—Growth of Knowledge of Earth Structure. 


‘‘There is reason to believe that Mount Toby, the strata of 
which are almost horizontal, exhibits the original dip of these 
rocks, and that those cases in which they are more highly inclined 
are the result of some Plutonian convulsion. Such irregularity 
in the dip of coal fields is no uncommon occurrence.’’ 


In Hitcheock’s Geology of Massachusetts, published in 
1833, ten years later, geological structure sections of the 
Connecticut Valley rocks are given, the facts are dis- 
cussed in detail and the dip ascribed to the elevatory 
forces. ‘Ele says (1--c., pp. 23, 223): 


‘“Tf it were possible to doubt that the new red sandstone 
formation was deposited from water, the surface of some of the 
layers of this shale would settle the question demonstrably. 
For it exhibits precisely those gentle undulations, which the 
loamy bottom of every river with a moderate current, presents. 
(No. 198.) But such a surface could never have been formed 
while the layers had that high inclination to the horizon, which 
many of them now present: so that we have here, also, decisive 
evidence that they have heen elevated subsequently to their 
deposition. 

The objection of a writer in the American Journal of Science. 
that such a height of waters as would deposit Mount Toby, must . 
have produced a lake nearly to the upper part of New Hamp- 
shire, in the Connecticut Valley, and thus have caused the same 
sandstone to be produced higher up that valley than Northfield. 
loses its force, when it is recollected that this formation was 
deposited before its strata were elevated. For the elevating 
_foree undoubtedly changed the relative level of different parts 
of the country. In this case, the disturbing force must have 
acted beneath the primary rocks. And besides, we have good 
evidence which will be shown by and by, that our new red 
sandstone was formed beneath the ocean. We cannot then 
reason on this subject from present levels.”’ 


In 1840, H. D. Rogers, a geologist who has acquired a 
more widely known name than Hitcheock, but who in 
reality showed an inferior ability in interpretation, made 
the following statements in explanation of the regional 
monoclinal dip of the New Jersey Triassic rocks averag- 
ing 15 to 20 degrees to the northwest :? 


‘“Their materials give evidence of having been swept into this 
estuary, or great ancient river, from the south and southeast, 
by a current producing an almost universal dip of the beds 
towards the northwest, a feature clearly not caused by any 
uplifting agency, but assumed originally at the time of their 


1H. D. Rogers, Geology of New Jersey, Final Report, p. 115, 1840. 


Barrell—Growth of Knowledge of Earth Structure. 137 


deposition, in consequence of the setting of the current from the 
opposite or southeastern shore.’’ 


In 1842, at the third annual meeting of the Association 
of American Geologists both H. D. and W. B. Rogers 
argued (43, 170, 1842) against Sir Charles Lyell and E. 
Hiteheock that the present dip of the Triassic was the 
original slope of deposition, stating among other reasons 
that the footprints impressed upon the sediments often 
showed a slipping and a pushing of the soft clay in the 
direction of the downhill slope. In 1858 H. D. Rogers 
still held to the same views of original dip,” notwithstand- 
ing that a moderate amount of observation on the mud- 
cracked and rain-pitted layers would have supplied the 
proof that such must have dried as horizontal surfaces. 
The idea of inclined deposition is not yet wholly dead as 
it has been suggested more than once within the present 
generation as a means of escaping from the necessity of 
accepting the very great thicknesses of this and similar 
formations. Thus, as Brogger has remarked in another 
connection,—the ghosts of the old time stand ever ready 
to reappear. 

In the present essay on the rise of structural geology 
as reflected through a century of publication in this 
Journal, attention will be given especially to two fields, 
that of structures connected with igneous rocks and that 
of structures connected with mountain making, and 
emphasis will be placed upon the growth of understand- 
ing rather than upon the accumulating knowledge of 
details. The growth in both of these divisions of struc- 
tural geology is well illustrated in the volumes of the 
Journal. 


STRUCTURES AND RELATIONSHIPS OF IGNEous Rocks. 
Opposed Interpretations of Plutonists and Neptunists. 


During the first quarter of the nineteenth century the 
geologic controversy between the Plutonists and Nep- 
tunists savas at its height; the Plutonists, following the 
Scotchman, Hutton, holding to the igneous origin of 
basalt and granite, the Neptunists, after their German 
master, Werner of Freiberg, maintaining that these 
rocks had been precipitated from a primitive universal 
ocean. The Plutonists, although time has shown them to 

* H. D. Rogers, Geology of Pennsylvania, vol. 2, pt. II, pp. 761, 762, 1858. 


138 Barrell—Growth of Knowledge of Earth Structure. 


have been correct in all essential particulars, were for a 
generation submerged under the propaganda carried for- 
ward by the disciples of Werner. The ‘‘Illustrations of 
the Huttonian Theory of the Earth,’’ a remarkable clas- 
sic, worthy of being studied to-day as well as a century 
ago, was published in 1802 by John Playfair, professor of 
mathematics in the University of Edinburgh and a friend 
of Hutton, who had died five years previously. This 
volume was opposed by Robert Jameson, professor of nat- 
ural philosophy in the same university, who had absorbed 
the ideas of the German school while at Freiberg 
and published in 1808 a volume on the ‘‘Klements of 
Geognosy,’’ in which the philosophy of Werner is fol- 
lowed throughout and even obsidian and pumice are 
argued to be aqueous precipitates. The authority of the 
Wernerian autocracy caused its nomenclature to be 
adopted:in the new world, but strong evidence against 
its interpretations was to be found in the actual struc- 
tural relations disptayed by the igneous rocks. 


Contributions on Volcanic and Intruswe Rocks. 


The accumulation and study of facts constituted the 
best cure for an erroneous theory. The publications of 
the Journal contributed toward this end by articles along 
several lines, the most original contributions were those 
which dealt with the areal and structural geology of 
-eastern North America, but equally valuable at that 
time for the broadening of scientific interest were 
the studies on the volcanic activities of the Hawaian 
Tslands, published through many years. Perhaps most 
valuable from the educative standpoint were the exten- 
sive republications in the Journal of the more important 
European researches, making them accessible to Ameri- 
ean readers. In volume 13 (1828), for example, a digest 
of Scrope’s work on volcanoes is given, covering forty 
pages; and of Daubeny on active and extinct volcanoes, 
running over seventy-five pages and extending into vol. 
14. Through these comprehensive studies the nature of 
voleanie action became generally understood during the 
first half of the nineteenth century and the original pub- 
lications in the Journal were valuable in giving a knowl- 
edge of the activities of the Hawaiian volcanoes. 

Karly in the nineteenth century the whole of America 
still remained to be explored by the geologist. The 


Barrell—Growth of Knowledge of Earth Structure. 1389 


regions adjacent to the centers of learning were among 
the first to receive attention and the Triassic basin of 
Connecticut and Massachusetts yielded information in 
regard to the nature of igneous intrusion. This basin, 
of unmetamorphic shales and sandstones, is occupied by 
the Connecticut River except at its southern end. The 
Formation contains within it sills, dikes, and outflows of 
basaltic rocks which because of their superior resistance 
to erosion constitute prominent hills, in places bounded 
by cliffs. 

Silliman in 1806* deseribed East Rock, New Haven, 
Connecticut, as a whinstone, trap, or basalt, and 
accounted for its presence on the supposition that it had: 


‘actually been melted in the bowels of the earth and ejected 
among the superior strata by the force of subterraneous fire, 
but never erupted like lava, cooling under the pressure of the 
superincumbent strata and therefore compact or nonvesicular, 
its present form being due to erosion.”’ 


In these conclusions Silliman was correct. With but a 
limited amount of experience he was able to discriminate 
between the intrusive and effusive rocks and saw that the 
prominence of this hill was due to the erosion of the sedi- 
ments which once surrounded it. 

An extensive paper on the geology of this region was 
published by Edward Hitchcock in 1823,* then just thirty 
years of age. This paper shows the evidence of exten- 
sive field observations, and his comments in regard to 
the trap and granite are of interest. Hitchcock gives 
five pages to the subject of ‘‘Greenstone Dykes in Old 
Red Sandstone’’ (6, 56-60, 1823) and makes the follow- 
ing statements: 


‘Professor Silliman conducted me to an interesting locality 
of these in East-Haven. They occur on the main road from 
New-Haven to East-Haven, less than half a mile from Tomlin- 
Sons bridge’. ©. . (p. 56). 

They are an interesting feature in our geology, and deserve 
more attention; and it is peculiarly fortunate that they should 
be situated so near a geological school and the first mineral 
eabinet in our country . . . (p. 58). 

* Connecticut Academy of Arts and Sciences, 1810; quoted by G. P. 
Merrill in Contributions to the History of North American geology, Ann. 
Rpt. Smithsonian Institution for 1904, p. 216. 

*A Sketch of the geology, mineralogy, and scenery of the regions con- 
tiguous to the river Connecticut; with a geological map and drawings of 


organic remains; and occasional botanical notices, this Journal, 6, 1-86, 
201-236, 1823; 7, 1-30, 1824. 


140 Barrell—Growth of Knowledge of Earth Structure. 


Origin of Greenstone. 


Does the greenstone of the Connecticut afford evidence in 
favour of the Wernerian or of the Huttonian theory of its 
origin? Averse as I feel to taking a side in this controversy, I 
cannot but say, that the man who maintains, in its length and 
breadth, the original hypothesis of Werner in regard to the 
aqueous deposition of trap, will find it for his interest, if he 
wishes to keep clear of doubts, not to follow the example of 
D’Aubuisson, by going forth to examine the greenstone of this 
region, lest, like that geologist, he should be compelled, not only 
to abandon his theory, but to write a book against it. Indeed, 
when surveying particular portions of this rock, I have some- 
times thought Bakewell did not much exaggerate when he said 
in regard to Werner’s hypothesis, that, ‘it is hardly possible 
for the human mind to invent a system more repugnant to 
existing facts.’ 

On the other hand, the Huttonian would. doubtless have his 
heart gladdened, and his faith strengthened by a survey of the 
greater part of this rock. As he looked at the dikes of the old 
red sandstone, he would almost see the melted rock forcing its 
way through the fissures; and when he came to the amygdaloi- 
dal, especially to that variety which resembles lava, he might 
even be tempted to apply his thermometer to it, in the suspicion 
. that it was not yet quite cool . . . (p. 59). 

By treating the subject in this manner I mean no disrespect 
to any of the distinguished men who have adopted either side of 
this question. To President Cooper especially, who regards the 
ereenstone of the Connecticut as voleanic, I feel much indebted 
for the great mass of facts he has collected on the subject. And 
were I to adopt any hypothesis in regard to the origin of our 
greenstone, it would be one not much different from his’’ (p. 60). 


By 1833 and more clearly in 1841 Hitchcock had come 
to recognize the distinction between intrusive and extru- 
sive basaltic sheets in the Connecticut valley. Dawson 
also came to regard the Acadian sheets as extrusive, and 
Emerson in 1882 recalled again the evidence for Massa- 
chusetts (24, 195, 1882). Davis, however, went a step 
further and by applying distinctive criteria not only sep- 
arated intrusive and extrusive sheets throughout the 
whole Triassic area, but by using basalt flows as strati- 
eraphic horizons unraveled for the first time the system 
of faults which cut the Triassic system. His preliminary 
paper (24, 345, 1882) was followed by many others. 

From 1880 onward begins the period of precise struc- 
tural field work. The older geologists mostly conceived 
their work after reconnaissance methods. From 1870 to 


o 


Barrell—Growth of Knowledge of Earth Structure, 141 


1880 a group of younger men entered geology who paid 
close attention to the solid geometry and mechanics of 
earth structures. In their hands physical and dynamical 
geology began to assume the standing of a precise and 
quantitative science. In the field of intrusive rocks the 
opening classic was by Gilbert, who in his volume on the 
eeology of the Henry Mountains, published in 1880, made 
laccoliths known to the world. With the beginning of 
this new period we may well leave the subject of intru- 
sive rocks and turn to the progress of knowledge in 
regard to those deeper and vaster bodies now known as 
batholiths. These, since erosion does not expose their 
bottoms, Daly separates from intrusives and classifies as 
subjacent. The batholiths consist typically of granite 
and granodiorite, and introduce us to the problem of 
granite. 


Views on the Structural Relations of Granite. 


Conscientious field observations were sufficient to 
establish the true nature of the intrusive and extrusive 
rocks. The case was very different, however, with the 
nature and relations of the great bodies of granite, 
which may be taken in the structural sense as including 
all the visibly crystalline acidic and intermediate rocks, 
known more specifically as granite, syenite, and diorite. 

The large bodies of granite, structurally classified as 
stocks, or batholiths, commonly show wedges, tongues, or 
dike networks cutting into the surrounding rocks. The 
relations, however, are not all so simple as this. Gran- 
ites may cover vast areas, they are usually the older 
rocks, they are generally associated with regional 
metamorphism of the intruded formations, which meta- 
morphism is now understood to be due chiefly to the heat 
and mineralizers given off from the granite magma, asso- 
ciated with mashing and shearing of the surrounding 
rocks. The granite was often injected in successive 
stages which alternated with the stages of regional mash- 
ing. A parallel or gneissic structure is thus developed 
which is in part due to mashing, in part to igneous injec- 
tion. Where the ascent of heat into the cover is exces- 
sive, or where blocks are detached and involved in the 
magma, the latter may dissolve some of the older cover 
rocks, even where these were of sedimentary origin. 


142 Barrell—Growth of Knowledge of Earth Structure. 


Thus between mashing, injection, and assimilation the 
genetic relationships of a batholith to its surroundings 
are in many instances obscure. Nevertheless, attention 
to the larger relations shows that the molten magma orig- 
inated at great depths in the earth’s crust, far below the 
bottoms of geosynclines, and consists of primary igneous 
material, not of fused sediments. From those depths it 
has ascended by various processes into the outer crust, - 
where it crystallized into granite masses, to be later 
exposed by erosion. The amount of material which can 
be dissolved and assimilated must be small in compari- 
son with the whole body of the magma. The original 
composition of the magma was probably basic, nearer 
that of a basalt than that of a granite. Differentiation 
of the molten mass is thought to cause the upper and 
lower parts of the chamber to become unlike, the lighter 
and more acidic portion giving rise to the great bodies of 
granite. With the exception of certain border zones the 
whole, however, is regarded as igneous rock risen from 
the depths. 

The complex border relations, but more particularly 
certain academic hypotheses, led toa period of misunder- 
standing and retrogression in regard to the nature of 
oranites. It constitutes an interesting illustration of. 
. the possibility of a wrong theory leading interpretation 
astray, chiefly through the magnification of minor into 
major factors. This history illustrates the dangers of 
qualitative science as compared to quantitative, of a 
single hypothesis as matched against the method of mul- 
tiple working hypothesis. This flux of opinion in regard 
to the nature of granites may be traced through the vol- 
umes of the Journal. | 

EK. Hitchcock in 1824 (6, 12) noted that in places gran- 
ite appeared bedded, but in other places existed in veins 
which cut obliquely across the strata. Silliman, although 
careful not to deny the aqueous origin of some basalts, 
yet held that the field evidence of New England indicates 
for that region the igneous or Huttonian origin of Hep 
and granite (7, 238, 1824), 

In 1832 the following article by Hitchcock appeared in 
the Journal (22, 1, 70) : 


Report on the Geology of Massachusetts; examined under the 
direction of the Government of that State, during the years 


Barrell—Growth of Knowledge of Earth Structure. 148 


1830 and 1831; by Edward Hitcheock, Prof. of Chemistry and 
Natural History in Amherst College. 

A footnote adds that this is ‘‘published in this Journal by 
consent of the Government of Massachusetts, and intended to 
appear also in a separate form, and to be distributed among the 
members of the Legislature of the same State, about the time 
of its appearance in this work. It is, we believe, the first exam- 
ple in this country, of the geological survey of an entire State.’’ 


This article includes a geological map of the state and 
covers the subject of economic geology. The report 
brought forth the following remarks from a French 
reviewer in the Revue Encyclopédique, Aug. 1832, quoted 
in the Journal (23, 389, 1833) : 


‘*A single glance at this report, is sufficient to convince any 
one of the utility of such a work, to the state which has under- 
taken it; and to regret that there is so very small a part of the 
French territory, whose geological constitution is as well known 
to the public, as is now the state of Massachusetts. France has 
the greater cause to regret her being distanced in this race by 
America, from her having a corps of mining engineers, who 
if they had the means, would, in a very short time furnish a 
work of the same kind, still more complete, of each of the 
departments. ’’ 


The complete report published in 1833 is a work of 700 
pages. Pages 465 to 517 are devoted to the subject of 
granite. Numerous detailed sketches are given showing 
contact relations. Nine pages are given to theoretical 
considerations and many lines of proof are given that 
granite 1s an igneous rock, molten from the internal heat 
of the earth, and intruded into the sedimentary strata. 
His statement is the clearest published in the world, so 
far as the writer is aware, up to that date, and marks 
Edward Hitchcock as one of the leading geologists of his 
generation in Europe as well as America. Unfortu- 
nately his views were largely lost to sight during the fol- 
lowing generation. 

In 1840 the first American edition of Mantell’s Won- 
ders of Geology gave currency to the idea that granite is 
proved to be of all geological ages up to the Tertiary 
(39, 6, 1840). In 1843 J. D. Dana pointed out (45, 104) 
that schistosity was no evidence of sedimentary origin. 
He regarded most granites as igneous as shown by their 
structural relations, but considers that some may have 
had a sedimentary origin. 


« 


144 Barrell—Growth of Knowledge of Earth Structure. 


_ Rise and Decline of the Metamorphic Theory of Granite. 


Up to 1860 granite was regarded on the basis 
of the facts of the field as essentially an intrusive 
rock, but gneiss as a metamorphic product mostly of sedi- 
mentary origin. It seemed as though sound methods of 
research and interpretation were securely established. 
Nevertheless, a new era of speculation and a modified 
Wernerism arose at that time with a paper by T. Sterry 
Hunt, marking a retrogression in the theory of granite 
which lasted until his death in 1892. 7 

In November, 1859, Hunt read before the Geological 
Society of London a paper on ‘‘Some Points in Chemical 


Geology’’ in which he announced that igneous rocks are © 


in all cases simply fused and displaced sediments, the 
fusion taking place by the rise of the earth’s internal 
heat into deeply buried and water-soaked masses of sedi- 
ments (see 30, 183, 1860). The germ of this idea of 
aqueo-lgneous fusion was far older, due to Babbage and 
John Herschel, neither of them geologists, but such 
sweeping extensions of it had never before been pub- 
lished. Hunt had the advantage of a wide acquaintance- 
ship with geological literature and chemistry.. He wrote 
plausibly on chemical and theoretical geology, but his 
views were not controlled by careful field observations. 
In fact he wrote confidently on regions which apparently 
he had never seen and where a limited amount of field 
work would have shown him to have been fundamentally 
in error. A man of egotistical temperament, he sought 
to establish priority for himself in many subjects and in 
order to cover the field made many poorly founded asser- 


tions. Building on to another Wernerian idea, he held’ 


that many metamorphic minerals had a chronologic value 
comparable to fossils—staurolite for example indicating 
a pre-Silurian age—and on this basis divided the erystal- 


line rocks into five series. Although there is much of | 


value buried in Hunt’s work it is difficult to disentangle 
it, with the result that his writings were a disservice to 
the science of geology. Although carrying much weight 
in his lifetime, they have passed with his death nearly 
into oblivion. 

Marcou, with a limited knowledge of American geol- 
ogy, and but little respect for the opinions of others, had 
published a geologic map of the United States containing 


eS 


Barrell—Growth of Knowledge of Earth Structure, 145 


eross errors. In support of his views he read in Novem- 
ber, 1861, a paper on the Taconic and Lower Silurian 
Rocks of Vermont and Canada. In the following year 
he was severely reviewed by ‘‘T’,’? who states positively 
in controverting Marcou (33, 282, 283, 1862) that ‘‘the 
eranites (of the Green Mountains) are evidently strata 
altered in place.”’ 


‘*Mr. Marecou should further be informed that the granites 
of the Alpine summits, instead of being, as was once supposed. 
eruptive rocks, are now known to be altered strata of newer 
Secondary and Tertiary age. A simple structure holds good in 
the British Islands, where as Sir Roderick Murchison has shown 
in his recent Geological map of Scotland, Ben Nevis and Ben 
Lawers are found to be composed of higher strata, lying in 
synelinals. This great law of mountain structure would alone 
lead us to suppose that the eneiss of the Green mountains. 
instead of being at the base, is really at the summit of the series. 


We cannot here stop to discuss Mr. Marcou’s remark about 
‘the unstratified and oldest crystalline rocks of the White 
mountains’ which he places beneath the lower Taconic series. 
Mr. Lesley has shown that these granites are stratified, and with 
Mr. Hunt, regards them as of Devonian Age. (This Journal, 
vol. 31, p. 403.) Mr. Marcou has come among us with notions 
of mountains upheaved by intrusive granites, and similar anti- 
quated traditions, now, happily for science, well nigh forgotten.’’ 


It is seen that Marcou, notwithstanding the general 
character of his work, happened to be nearer right in 
some matters than were his erities, and that ‘‘T’’ had 
adopted to the limit the views of Hunt. 

The recovery of geology from this period of confusion — 
was partly owing to the slow accumulation of opposed 
facts; especially to a recognition of the fact that the 
overplaced relation of the granite gneisses in western 
Scotland was due to great overthrusts; also to the evi- 
dence of the clearly intrusive nature of many of the 
Cordilleran granites. The recovery of a sounder theory 
was hastened, however, by the application of criticisms 
by J. D: Dana in the Journal. In 1866 (42, 252) Dana 
pointed out that sedimentary rocks in Pennsylvania, in 
Nova Scotia, and other regions which had been buried to 
a depth of at least 16,000 feet are not metamorphic. 
Mere depth of burial of sediments was not sufficient 
therefore to produce metamorphism and aqueo-igneous 


146 Barrell—Growth of Knowledge of Earth Structure. 


fusion. The baseless and speculative character of the 
use of minerals as an index of age and of Hunt’s inter- 
pretation of New England geology in general was shown 
by Dana in 1872 (38, 91). The following year Dana 
pointed out clearly that igneous eruptions in general 
have been derived from a deep-seated source and did not 
come from the agueo-igneous fusion of sediments. As to 
gradations between true igneous rocks and fused and 
displaced sediments he makes the following statements 
(6, 114, 1873): 


‘‘Again, the plastic rock-material that may be derived from 
the fusion or semifusion of the supercrust, (that is, of rocks 
originally of sedimentary origin,) gives rise to ‘‘igneous’’ rocks 
often not distinguishable from other igneous rocks, when it is 
ejected through fissures far from its place of origin; while erys- 
talline rocks are simply metamorphic if they remain in their 
original relations to the associated rocks, or nearly so. 

Between these latter igneous rocks and the metamorphic there 
may ‘be indefinite gradations, as claimed by Hunt. But if our 
reasonings are right, the great part of igneous rocks can be 
proved to have had no such supercrust origin. The argument 
from the presence of moisture or of hydrous minerals in such 
rocks in favor of their origin from the fusion of sediments has 
been shown to be invalid.’’ . 


The injected marginal rocks and the post-intrusive 
metamorphism of most of the New England granites has, 
however, obscured more or less their real igneous nature 
so that the gradation from metamorphic sediments 
through igneous gneisses to granites could be read in 
either direction. These features misled Dana who 
accepted the prevailing idea of the general metamorphic 
origin of granite. Dana makes the following statement 
(6, 164, 1873): 


‘“‘But Hunt is right in holding that in general granite and 
syenite (the quartz-bearing syenite) are undoubtedly meta- 
morphic rocks where not vein-formations, as I know from the 
study of many examples of them in New England; and the 
veins are results of infiltration through heated moisture from 
the rocks adjoining some part of the opened fissures they fill.’’ 


Granite, although regarded at this time as the extreme 
of the metamorphic series and originating from sedi- 
ments, was looked upon as typically Archean in age, 
though in some cases younger. Such a doctrine per- 
mitted such extreme misinterpretations as that of 


Barrell—Growth of Knowledge of Earth Structure, 147 


Clarence King and S. F. Emmons on the nature of the 
intrusive granite of the Little Cottonwood canyon in the 
Wahsatch Range. This body cuts across 30,000 feet of 
Paleozoic rocks and to the careful observer, as later 
admitted by Emmons, shows clear evidence of its trans- 
eressive nature. But at that time it was generally con- 
sidered that granite mountains were capable of resist- 
ing the erosion of all geological time. Consequently it 
did not seem incredible to King and his associates that 
here a great granite range of Archean origin had stood 
up through Paleozoic time until gradual subsidence had 
permitted it to be buried beneath 30,000 feet of sedi- 
ments.° 

It may seem to the present day reader that such a mis- 
interpretation, doing violence to fundamental geologic 
knowledge as now recognized, was inexcusable; but in 
the light of the history of geology as here detailed it is 
seen to have been the interpretation natural to that time. 
It is true that a careful examination of the facts of that 
very field would have proved the post-Paleozoic and in- 
trusive nature of that great granite body now known 
as the Little Cottonwood batholith, but Emmons has 
explained the rapid and partial nature of the observa- 
tions which they were compelled to make in order to keep 
up to their schedule of progress (16, 139, 1903). 

Whitney had found some years earlier that the gran- 
ites of the Sierra Nevada were igneous rocks intrusive 
into the Triassic and Jurassic strata. The Lake Supe- 
rior geologists began to show in the eighties that granite 
was there an intrusive igneous rock. R. D. Irving and 
Wadsworth noted these relations. Lawson in 1887 
pointed out emphatically (33, 473) that the granites of 
the Rainy Lake region, although basal, were younger 
than the schists which lay above them. The granite- 
eneisses he held were of clearly the same igneous origin 
as the granites and neither gave any field evidence of 
being fused and displaced sediments. From this time 
forward the truly igneous nature of granite became 
increasingly accepted until now the notion of its being 
made of sedimentary rocks softened and recrystallized by 
the rise of the isogeotherms through deep burial is as 
obsolete as the still older doctrine of the Neptunists that 


®Clarence King, U. S. Geol. Exploration of the Fortieth Parallel, vol. 
1, pp. 16, 44-48, 1878. 


148 Barrell—Growth of Knowledge of Earth Structure. 


granite was laid down as a crystalline precipitate on the 
floor of the primitive ocean. 

The recognition of the truly igneous nature of granites 
has been followed in the present generation by a series 
of studies on their structural relations and mode of 
genesis. A number of important initial articles on vari- 
ous aspects of structure and contact relations have 
appeared in the Journal, but this sketch of the history of 


the subject may well stop with the introduction to this — 


modern period. 


OROGENIC STRUCTURES. 
Views of Plutonists and Neptunists. 


Orogenic structures are, as the name implies, those 
connected with the birth of mountains. Nearly synony- 
mous terms are deformative or secondary structures. 
On a small seale this division embraces the phenomena 
exposed in the rock ledge or quarry face, or in the dips 
and dislocations varying from one exposure to another. 
These structures include faults, folds, and foliation. On 
a larger scale are included the relations of the differ- 
ent ranges of a mountain system to each other, relations 
to previous geologic history, relations to the earth as a 
whole, and to the forces which have generated the struc- 
tures. 

In order to see the stage of development of this subject 
in 1818 and its progress as reflected through the publica- 
tions of a century, more particularly in this Journal, it 
is desirable to turn again to those two treatises emanat- 
ing from Edinburgh at the beginning of the nineteenth 
century and representing two opposite schools of 
thought, the Plutonists and Neptunists. 

Playfair, in 1802, devotes nineteen pages to the subject 
of the inflection and elevation of strata.° He places 
emphasis on the characteristic parallelism of the strike 
of the folds throughout a region, as shown through the 
intersection of the folds by a horizontal plane of erosion. 
He contrasts this with the arches shown in a transverse 
section and enlarges on our ability to study the deeply 
buried strata through the denudation of the folded struc- 
ture. He argues from these relations that the struc- 
tures can not be explained by the vague appeal of the 

$Tllustrations of the Huttonian Theory of the Earth, pp. 219-238, 1802. 


Barrell—Growth of Knowledge of Earth Structure, 149 


Neptunists to forces of crystallization, to slopes of orig- 
inal deposition, or to sinking in of the roofs of caverns. 
The causes he argues were heat combined with pressure. 
As to the directions in which the pressure acted he is not 
altogether clear, but apparently regards the pressure as 
acting in upward thrusts against the sedimentary planes, 
the latter yielding as warped surfaces. His method of 
presentation is that of inductive reasoning from facts, 
but he stopped short of the conception of horizontal com- 
pression through terrestrial contraction. 

Jameson, professor of natural history in the same uni- 
versity, in 1808 contemptuously ignores the work of Hut- 
ton and Playfair in what he calls the ‘‘monstrosities 
known under the name of Theories of the Earth.’’ Ina 
couple of pages he confuses and dismisses the whole sub- 
ject of deformation. He states: 


‘Tt is therefore a fact, that all inclined strata, with a very 
few exceptions, have been formed so originally, and do not owe 
their inclination to a subsequent change. 

When we examine the structure of a mountain, we must be 
careful that our observations be not too micrological, otherwise 
we shall undoubtedly fail in acquiring a distinct conception of 
it. This will appear evident when we refiect that the geognostic 
features of Nature are almost all on the great seale. In no case 
is this rule to be more strictly followed than in the examination 
of the stratified structure. 

By not attending to this mode of examination, geognosts 
have fallen into numberless errors, and have frequently given 
to extensive tracts of country a most irregular and confused 
structure. Speculators building on these errors have repre- 
sented the whole crust of the globe as an irregular and unseemly 
mass. It is indeed surprising, that men possessed of any knowl- 
edge of the beautiful harmony that prevails in the structure of 
organic beings could. for a moment believe it possible, that the 
ereat fabric of the globe itself—that magnificent display of 
Omnipotence,—should be destitute of all regularity in its strue- 
ture, and be nothing more than a heap of ruins.”’ 


This was the attitude of a leader of British opinion 
toward the subject of deformational geology from which 
the infant science had to recover before progress could be 
made. The early maps were essentially mineralogical 
and lithological. The order of superposition and the 
consequent sequence of age was regarded as settled by 
Werner in Germany and not requiring investigation in 


* Robert Jameson, Elements of Geognosy, pp. 55-57, 1808. 


150 Barrell—Growth of Knowledge of Earth Structure. 


America. The early examples of structure were sections 
drawn with exaggerated vertical scales and those of 
Maclure do not show detail. 


Recogmiion of Appalachian Structures. 


Following the founding of the Journal in 1818 there is 
observable a growth in the quality and detail of geologi- 
cal mapping. Dr. Aiken, professor of natural philosophy 
and chemistry in Mt. St. Mary’s College, published in the 
Journal in 1834 (26, 219) a vertical section extending 
between Baltimore and Wheeling, a distance of nearly 
250 miles, on a scale of about 7 miles per inch. The suc- 
cession of rocks is carefully shown and the direction of 
dip, but no attempt is made to show the underground 
relations, the stratigraphic sequence, and the folded 
structures which are so clear in that Appalachian section. 
The text also shows that the author had not recognized 
the folded structure. Furthermore, where the folds 
cease at the Alleghany mountain front, the flat strata are 
shown as resting unconformably on the folded rocks to 
the east. AR 

R. C. Taylor, geologist, civil and mining engineer, was 
from 1830 to 1835 the leading student of Pennsylvanian 
geology as shown by the publication in 1835 of four 
papers aggregating over 80 pages in the Transactions of 
the Geological Society of Pennsylvania. His work is 
noticeable for accuracy in detail and no doubt was influ- 
ential in setting a high standard for the state geological 
survey which immediately followed. 

H. D. and W. B. Rogers have been given credit in this 
country, and in Europe also, as being the leading 
expounders of Appalachian structure. Merrill speaks of 
H. D. Rogers as unquestionably the leading structural 
geologist of his time.8 To the writer, this attributed 
position appears to be due to his opportunities rather 
than to scientific acumen. The magnificent but readily 
decipherable folded structure of Pennsylvania, the rela- 
tionships of coal and iron to this structure, the consid- 
erable sums of money appropriated, and the work of a 
corps of able assistants were factors which made it com- 
paratively easy to reach important results. In ability to 


8G. P. Merrill, Contributions to the History ee American Geology. 
Report of the U. §. National Museum for 1904, p. 328 : 


Barrell—Growth of Knowledge of Earth Structure. 151 


weigh facts and interpret them Edward Hitchcock 
showed much more insight than H. D. Rogers, while in 
the philosophic and comprehensive aspects of the subject 
J. D. Dana far outranks him. 

H. D. Rogers in his first report on the geological sur- 
vey of New Jersey, 1836, recognizes that the Cambro- 
Silurian limestones (lower Secondary limestones) were 
deposited as nearly horizontal beds and the ridges of 
pre-Cambrian gneiss (Primary) had been pushed up as 
anticlinal axes (p. 128). He also clearly recognized the 
distinction between slaty cleavage and true dip as shown 
in the Ordovician slates (p. 97). Between 1836 and 1840 
he had learned a great deal on the nature of folds as is 
shown in his Pennsylvania report for 1839 and the struc- 
ture sections in his New Jersey report for 1840. 

R. C. Taylor, who had now become president of the 
board of directors of the Dauphin and Susquehanna Coal 
Company, published in the Journal in 1841 (41, 80) an 
unportant paper entitled ‘‘Notice of a Model of the 
Western portion of the Schuylkill or Southern Coal 
Field of Pennsylvania, in illustration of an Address to 
the Association of American Geologists, on the most 
appropriate modes for representing Geological Phe- 
nomena.’’ In this paper he calls attention to the value 
of modeling as a means of showing true relations in three 
dimensions. He condemns the custom prevalent among 
geologists of showing structure sections with an exag- 
gerated vertical scale with its resultant topographic and 
structural distortions. Taylor was widely acquainted 
with the structure of Pennsylvania, Maryland, and Vir- 
ginia. 


Nature of Forces Producing Folding. 


In 1825 Dr. J. H. Steele sent to Professor Silliman two 
detailed drawings and description of an overturned fold 
at Saratoga Lake, New York. As to the significance of 
this i Steele makes the following statement (9, 3, 
1825) :- 


‘“‘Tt is impossible to examine this locality without being 
strongly impressed with the belief that the position which the 
strata here assume could not have been effected in any other 
way than by a power operating from beneath upwards and at 
the same time possessing a progressive force; something analo- 
gous to what takes place in the breaking up of the ice of large 


152 Barrell—Growth of Knowledge of Earth Structure. 


rivers. The continued swelling of the stream first overcomes 
the resistance of its frozen surtace and having elevated it to a 
certain extent, it is forced into a vertical position, or thrown 
over upon the unbroken stratum behind, by the progressive 
power of the current.’’ 


So far as the present writer is aware this is the first 
recognition in geological literature of the evidence of a 
horizontally compressive and overturning force as a 
cause of folding. 

To K. Hitchcock belongs the credit of being the first to 
describe overturning and inversion of strata on a large 
scale, but without clearly recognizing it as such. In 
western Massachusetts metamorphism is extreme in the 
lower Paleozoic rocks in the vicinity of the overthrust 
mass of Archean granite-gneiss which constitutes the 
Hoosie range. The Paleozoic rocks of the valley to the 
west are overturned and appear to dip beneath the older 
rocks. Farther west the metamorphism fades out and 
the series assumes a normal position. Such an inverted 
relation, up to that time unknown, is described in 1833 as 
follows by Hitcheock in his Geology of Massachussetts 
(pp. 297, 298) : 


‘‘But a singular anomaly in the superposition of the series of 
rocks above described, presents a great difficulty in this ease. 
The strata of these rocks almost uniformly dip to the east: that 
is, the newer rocks seem to crop out beneath the older ones; so 
that the saccharine hmestone, associated with gneiss in the east- 
ern part of the range, seems to occupy the uppermost place in 
the series. Now as superposition is of more value in determin- 
ing the relative ages of rocks than their mineral characters, must 
we not conclude that the rocks, as we go westerly from Hoosac 
mountain, do in fact belong to older groups? ‘The petrifactions 
which some of them contain, and their decidedly fragmentary 
character, will not allow such a supposition to be indulged for 
a moment. It is impossible for a geologist to mistake the evi- 
dence, which he sees at almost every step, that he is passing 
from older to newer formations, just as soon as he begins to 
eross the valley of Berkshire towards the west. We are driven 
then to the alternative of supposing, either that there must be 
a deception in the apparent outcrop of the newer rocks from 
beneath the older, or that the whole series of strata has been 
actually thrown over, so as to bring the newest rocks at the bot- 
tom. The latter supposition is so improbable that I cannot at 
present admit it.’’ 


Barrell—Growth of Knowledge of Earth Structure, 153 


Hiteheoek tried to reconcile the evidence by a series of 
uncontformities and inclined deposition, but finds the solu- 
tion unsatisfactory. 

In this same year, 1833, Elie de Beaumont, a dis- 
tinguished French geologist, published his theory of the 
origin of mountains. He advanced the idea that since 
the globe was cooling it was condensing, and the crust, 
already cool, must suffer compression in adjusting itself 
to the shr inking molten interior. He concluded from the 
evidence shown in Europe that the collapse of the crust 
oceurred violently and rapidly at widely spaced intervals 
of time. This hypothesis introduced the idea of moun- 
tain folding by horizontal compressive forces. The the- 
oretical paper of de Beaumont, together with further 
observations by Hitchcock and others, led the latter in 
1841 to a final belief in the inversion of strata on a large 
scale by horizontal compression. His conclusions are 
expressed in an important paper published in the Journal 
(41, 268, 1841) and given on April 8, 1841, as the First 
Anniversary Presidential Address before the Associa- 
tion of American Geologists. This comprehensive sum- 
mary of American geology occupies 43 pages. Three 
pages are given to the inverted structure of the Appa- 
lachians from which the following paragraphs may be 
quoted: 


““We have all read of the enormous dislocations and inver- 
sions of the strata of the Alps; and similar phenomena are said 
to exist in the Andes. Will it be believed, that we have an 
example in the United States on a still more magnificent scale 
than any yet described ? 

Let us suppose the strata between Hudson and Connecticut 
rivers, while yet in the plastic state, (and the supposition may 
be extended to any other section across this belt of country from 
Canada to Alabama,) and while only slightly elevated, were 
acted upon by a force at the two rivers, exerted in opposite 
directions. If powerful enough, it might cause them to fold 
up into several ridges; and if more powerful along the western 
than the eastern side, they might fall over so as to take an 
inverted “dip, without producing any remarkable dislocations, 
while subsequent denudation would give to the surface its 
present outline. 

Fourthly, we should readily admit that such a plication and 
inversion of the strata might take place on a small seale. If for 
instance, we were to press against the extremities of a series of 
plastic layers two feet long, they could easily be made to assume 


154 Barrell—Growth of Knowledge of Earth Structure. 


the position into which the rocks under consideration are thrown. 
Why then should we not be equally ready to admit that this 
might as easily be done, over a breadth of fifty miles, and a 
length of twelve hundred, provided we can find in nature, forces 
sufficiently powerful? Finally, such forces do exist in nature, 
and have often been in operation.’’ 


The advanced nature of these conceptions may be 
appreciated by contrasting them with those put forth by 
H. D. and W. B. Rogers on April 29, 1842, before the third 
annual meeting of the same body (43, 177, 1842) and 
repeated by them before the British Association at Man- 
chester two months later. In their own words, the 
Rogers brothers from their studies on the folds shown in 
Pennsylvania and Virginia, conceived mountain folds in 
general to be produced by much elastic vapor escaping 
through many parallel fissures formed in succession, pro- 
ducing violent propulsive wave oscillations on the sur- 
face of the fluid earth beneath a thin crust. Thus actual 
billows are assumed to have rolled along through the 
crust. They did not think tangential pressure alone 
could produce folds. Such pressures were regarded as 
secondary, produced by the propagation of the waves and 
the only expression of tangential forces which they 
admitted was to fix the folds and hold them in position 
after the violent oscillation had subsided (44, 360, 1843). 
The leading British geologists De la Beche and Sedg- 
wick criticized adversely this remarkable theory, stating 
that they could see no such analogy in mountain folds to 
violent earthquake waves and that in their opinion the 
slow application of tangential force was sufficient to. 
account for the phenomena (44, 362-365, 1843). 

H. D. Rogers in the prosecution of the geological sur- 
vey of Pennsylvania displayed notable organizing ability 
and persistence in accomplishment, even to advancing per- 
sonally considerable sums of money, trusting to the state 
legislature to later reimburse him. Finally, after many 
delays by the state, the publication was placed directly 
in his charge and he produced in 1858 a magnificent 
quarto work of over 1,600 pages, handsomely illustrated, 
and accompanied by an atlas. It is excellent from the 
descriptive standpoint, standing in the first class. Meas- 
ured as a contribution to the theory of dynamical geol-— 
ogy, the explanatory portions were, however, thirty years 
behind the times. The same hypotheses are put forth 


Barrell—Growth of Knowledge of Earth Structure. 155 


in 1858 as in 1842. There is no acceptance of the views 
of Lyell concerning the uniformitarian principles 
expounded by this British leader in 1830, or of the nature 
of orogenic forces as published by Elie de Beaumont in 
1833. Rogers rejects the view that cleavage is due to 
compression and suggests ‘‘that both cleavage and folia- 
tion are due to the parallel transmission of planes or 
waves of heat, awakening the molecular forces, and 
determining their direction.2 Thus a mere maze of 
words takes the place of inductive demonstrations 
already published. 

In following the play of these opposing currents of 
geologic thought we reach now the point where a period 
of brilliant progress in the knowledge of mountains and 
of continental structures begins in the work of J. D. 
Dana. In 1842 Dana returned from the Wilkes Explor- 
ing Expedition and the following year began the publica- 
tion of the series of papers which for the next half 
century marked him as the leader in geologic theory in 
America. His work is of course to be judged against 
the background of his times. His papers mark distinct 
advances in many lines and are characterized throughout 
by breadth of conception and especially by clear and log- 
ical thinking. His work was published very largely in 
the Journal, of which after a few years he became chief 
editor. His first contribution on the subject of moun- 
tain structures, entitled ‘‘Geological results of the earth’s 
contraction in consequence of cooling,’’ was published in 
1847 (3,176). The evidence of horizontal pressure was 
first perceived in France as shown by the features of the 
Alps. Ehe de Beaumont connected it, by means of the 
theory of a cooling and contracting globe, with the other 
large fact of the increase of temperature with descent in 
the erust. Dana credits the Rogers brothers with first 
making known the folded structures of the Appalachians, 
but objects to their interpretation of origin. He showed 
by means of diagrams that the folds are to be explained 
by lateral pressure, the direction of overturning indicat- 
ing the direction from which the driving force proceeded. 

The Rogers brothers and especially James Hall, in 
working out the Appalachian stratigraphy, had noted 
that the formations, although accumulating to a maxi- 
mum thickness of between 30,000 and 49,000 feet, showed 


°H. D. Rogers, Geology of Pennsylvania, vol. 2, p. 916, 1858. 


156 Barrell—Growth of Knowledge of Earth Structure. 


evidences that the successive formations were deposited 
in shallow water. It suggested to them that the weight of 
the accumulating sediments was the cause of subsidence, 
each foot of sediment causing a foot of down sinking. 
This idea has continued to run through various text 
books in geology for half a century, yet Dana early 
saw the fallacy and in 1863 in‘the first edition of 
his Manual of Geology (p. 717) states ‘‘whether this 
is an actual cause or not in geological dynamics is 
questionable.’’ In 1866 in an important article on 
‘“‘Observations on the origins of some of the earth’s 
features,’’ Dana deals more fully and finally with 
this subject (42, 205, 252, 1866). He shows that such an 
effect of accumulating sediment postulates a delicate 
balance, a very thin crust and no resistance below. If 
such a weakness were granted it would be impossible for 
the earth to hold up mountains. Furthermore such sub- 
sidence was not regular during its progress and finally 
in the long course of geologic time gave place to a reverse 
movement of elevation. 

Hall had pointed out the fact that the sediments were 
thickest on the east in the region of mountain folding and 
thinned out to a fraction of this thickness in the broad 
Mississippi basin. Hall argued that the mere subsidence 
of the trough would produce the observed folding and 
that the folding was unrelated to mountain making or 
crustal shortening. In supposed proof he cited the fact 
that the Catskills consist of unfolded rock, are higher 
than the folded region to the south, and nearly as high as 
the highest metamorphic mountains to the east.1° Hall 
and all his contemporaries were handicapped in their 
geological theories by a complete inappreciation of the 
importance of subaérial denudation. Fer subscribing to 
these errors of their time even the ablest men should not 
be held responsible. Hall was the most forcible person- 
ality in geology in his generation. His contributions to 
paleontology were superb. His perception of the rela- 
tion existing between troughs of thick sediments and 
folded structures was a contribution of the first 1mport- 
ance; yet in the structural field his argument as to the 
production of the Appalachian folds by mere subsidence 
during deposition indicates a remarkable inability to 
apply the logical consequences of his hypothesis to the 


1 James Hall, Natural History of New York, Paleontology, vol. 3, pp. 
51-73, 1859. 


Barrell—Growth of Knowledge of Earth Structure, 157 


nature of the folds as already made known by the Rogers. 
Dana pointed out in reply to Hall that the folding did not 
correspond to the requirements of Hall’s hypothesis, 
especially as the folding took place not during, but after 
the close of the vast Paleozoic deposition. Dana states 
in conclusion on Hall’s hypothesis (42, 209, 1866) that 
‘Tt is a theory of the origin of mountains with the origin 
of mountains left out.’’ 


The Theory of Geosynclines and Geanticlines. 


The fact that systems of folded strata lie along axes of 

especially thick sediments and that this implied subsi- 
dence during deposition was Hall’s contribution to geo- 
logic theory, but curiously enough he failed, as shown, to 
connect it with the subsequent nature of mountain fold- 
ing. He did not see why such troughs should be weak to 
resist horizontal compression. The clear recognition of 
this relationship was the contribution of Le Conte, who 
in a paper on ‘‘A theory of the formation of the great 
features of the earth’s surface’’ (4, 345, 460, 1872), 
reached the conclusion that ‘‘mountain chains are 
formed by the mashing together and the up-swelling of 
sea bottoms where immense thicknesses of sediment have 
accumulated. ’’ 
_ As to the cause why mashing should take place along 
troughs of thick sediments Le Conte adopts the hypothe- 
sis of aqueo-igneous fusion proposed independently long 
before by Babbage and Herschel and elaborated into a 
theory of igneous rocks by Hunt. Under this view, as the 
older sediments became deeply buried, the heat of the 
earth’s interior ascended into them, and since they 
included the water of sedimentation a softening and met- 
amorphism resulted. Dana had shown, however, six 
years previously (42, 252, 1866), as the following quota- 
tion will indicate, that metamorphism of sediments 
required more than deep burial and that no such weaken- 
ing as was postulated by Herschel had occurred: 


‘“The correctness of Herschel’s principle cannot be doubted. 
But the question of its actual agency in ordinary metamorphism 
must be decided by an appeal to facts; and on this point I would 
here present a few facts for consideration. 

The numbers and boldness of the flexures in the rocks of most 
metamorphic regions have always seemed to me to bear against 


158 Barrell—Growth of Knowledge of E arth Structure. 


the view that the heat causing the change had ascended by the 
very quiet method recognized in this theory. 

But there are other facts indicating a limited sufficiency to 
this means of metamorphism. These are afforded by the great 
faults and sections of strata open to examination. In the Appa- 
lachian region, both of Virginia and Pennsylvania, faults occur, 
as described by the Professors Rogers, and by Mr. J. P. Lesley, 
which afford us important data for conclusions. Mr. Lesley, an 
excellent geologist and geological observer, who has explored 
personally the regions referred to, states that at the great fault 
of Juniata and Blair Cos., Pennsylvania, the rocks of the Tren- 
ton period are brought up to a level with those of the Chemung, 
making a dislocation of at least 16,000, and probably of 20,000, 
feet. And yet the Trenton limestone and Hudson River shales 
are not metamorphic. Some local cases of alteration occur there, 
including patches of roofing slate; but the greater part of the 
shales are no harder than the ordinary shales of the Pennsyl- 
vania Coal formation. 

At a depth of 16,000 feet the temperature of the earth’s crust, 
allowing an increase of 1° F. for 60 feet of descent, would be 
-about 330° F.; or with 1° F. for 50 feet, about 380° F.—either 
of which temperatures is far above the boiling point of water; 
and with the thinner crust of Paleozoic time the temperature 
at this depth should have been still higher. But, notwithstand- 
ing this heat, and also the compression from so great an over- 
lying mass, the limestones and shales are not crystalline. The 
change of parts of the shale to roofing slate is no evidence in 
favor of the efficiency of the alleged cause; for such a cause 
should act uniformly over great areas.”’ 


The next contribution to the theory of orogeny was a 
series of papers published in 1873 by Dana, entitled ‘‘On 
some results of the earth’s contraction from cooling, 
including a discussion on the origin of mountains and 
the nature of the earth’s interior.’ This contribution, 
viewed as a whole, ranks among the first half dozen 
papers on the science of mountains. The following 
quoted paragraphs give a view of the scope of this 
article: 


“Kinds and Structure of Mountams.’’ 


‘While mountains and mountain chains all over the world, 
and low lands, also, have undergone uplifts, in the course of 
their long history, that are not explained on the idea that all 
mountain elevating is simply what may come from plication 
or crushing, the component parts of mountain chains, or those 

This Journal, 5, 423-443, 474, 475; 6, 6-14, 104-115, 161-172, 304, 381, 
382, 1873 - 


Barrell—Growth of Knowledge of Earth Structure. 159 


simple mountains or mountain ranges that are the product of 
one process of making—may have received, at the tume of their 
original making, no elevation beyond that resulting from 
plication. 

This leads us to a grand distinction in orography, hitherto 
neglected, which is fundamental and of the highest interest in 
dynamical geology; a distinction between— 

1. <A simple or individual mountain mass or range, which is 
the result of one process of making, like an individual in any 
process of evolution, and which may be distinguished as a mono- 
genetic range, being one in genesis; and 

2. A composite or polygenetic range or chain, made up of 
two or more monogenetic ranges combined. 

The Appalachian chain—the mountain region along the 
Atlantic border of North America—is a polygenetic chain; it 
consists, like the Rocky and other mountain chains, of several 
monogenetic ranges, the more important of which are: 1. The 
Highland range (including the Blue Ridge or parts of it, and 
the Adirondacks also, if these belong to the same process of 
making) pre-Silurian in formation; 2. The Green Mountain 
range, in western New England and eastern New York, com- 
pleted essentially after the Lower Silurian era or during its 
closing period; 3. The Alleghany range, extending from south- 
ern New York southwestward to Alabama, and completed 
immediately after the Carboniferous age. 

The making of the Alleghany range was carried forward at 
first through a long-continued subsidence—a geosynclinal (not 
a true synclinal, since the rocks of the bending crust may have 
had in them many true or simple synclinals as well as anti- 
clinals), and a consequent accumulation of sediments, which 
occupied the whole of Paleozoic time; and it was completed, 
finally, in great breakings, faultings and foldings or plications 
of the strata, along with other results of disturbance. 

““These examples exhibit the characteristics of a large class 
of mountain masses or ranges. A geosynclinal accompanied by 
sedimentary depositions, and ending in a catastrophe of plica- 
tions and solidification, are the essential steps, while metamor- 
phism and igneous ejections are incidental results. The process 
is one that produces final stability in the mass and its annexation 
generally to the more stable part of the continent, though not 
stable against future oscillations of level of wider range, nor 
against denudation. 

It is apparent that in such a process of formation elevation 
by direct uplift of the underlying crust has no necessary place. 
The attending plications may make elevations on a vast scale 
and so also may the shoves upward along the lines of fracture, 
and crushing may sometimes add to the effect; but elevation 
from an upward movement of the downward bent crust is only 
an incidental concomitant, if it occur at all. 


160 Barrell—Growth of Knowledge of Earth Structure. 


We perceive thus where the truth les in. Professor Le Conte’s 
important principle. It should have in view alone monogenetic 
mountains and these only at the time of their making. It will 
then read, plication and shovings along fractures bemg made 
more promiment than crushing: 

Pheation, shoving along fractures and crushing are the true 
sources of the elevation that takes place during the making of 
eeosyneclinal monogenetic mountains. 

And the statement of Professor Hall may be made right if 
we recognize the same distinction, and, also, reverse the order 
and causal relation of the two events, accumulation and sub- 
sidence; and so make it read: 

Regions of monogenetic mountains were, previous, and pre- 
paratory, to the making of the mountains, areas each of a slowly 
progressing geosynelinal, and, consequently, of thick accumula- 
tions of sediments. 

The prominence and importance in orography of the moun- 
tain individualities described above as originating through a 
eeosynclinal make it desirable that they should have a distine- 
tive name; and I therefore propose to call a mountain range 
of this kind a synclinorium, from synclinal and the Greek épos, 
mountain. 

This brings us to another important distinction in orographie 
eeolozy—that of a second kind of monogenetic mountain. The 
synclinoria were made through a progressing geosynclinal. 
Those of the second kind, here referred to, were produced by a 
progressing geanticlinal. They are simply the upward bendings 
in the oscillations of the earth’s crust—the geanticlinal waves, 
and hardly require a special name. Yet, if one is desired, the 
term anticlinorium, the correlate of synclinorium, would be 
appropriate. Many of them have disappeared in the course of 
the oscillations; and yet, some may have been for a time— 
perhaps millions of years—respectable mountains. 

The geosynclinal ranges or synelinoria have experienced in 
almost all cases, since their completion, true elevation through 
creat geanticlinal movements, but movements that embraced a 
wider range of crust than that concerned in the preceding geo- 
svnelinal movements, indeed a range of crust that comes strictly 
under the designation of a polygenetic mass.’’ 


“<The Condition of the Earth’s Intersor.’’ 


‘‘The condition of the earth’s interior is not among the geo- 
logical results of contraction from cooling. But these results 
offer an argument of great weight respecting the earth’s interior 
condition, and make it desirable that the subject should be dis- 
cussed in this connection. Moreover, the facts throw additional 
light on the preceding topic—the origin of mountains. 


Barrell—Growth of Knowledge of Earth Structure. 161 


It seems now to be demonstrated by astronomical and physical 
arguments—arguments that are independent, it should be noted, 
of direct geological observation—that the interior of our globe 
is essentially solid. But the great oscillations of the earth’s 
surface, which have seemed to demand for explanation a liquid 
interior, still remain facts, and present apparently a greater 
difficulty than ever to the geologist. Professor Le Conte’s views, 
in volume iv, were offered by him as a method of meeting this 
diffieulty; yet, as he admits in his concluding remarks, the 
oscillations over the interior of a continent, and the fact of the 
ereater movements on the borders of the larger ocean, were 
left by him unexplained. Yet these oscillations are not more 
real than the changes of level or greater oscillations which 
oceurred along the sea border, where mountains were the final 
result; and this being a demonstrated truth, no less than the 
general solidity of the earth’s interior, the question comes up, 
how are the two truths compatible? 

The geological argument on the subject (the only one within 
our present purpose) has often been presented. But it derives 
new force and gives clearer revelations when the facts are viewed 
in the heht of the principles that have been explained in the 
preceding part of this memoir. 

The Appalachian subsidence in the Alleghany region of 35,000 
to 40,000 feet, going on through all the Paleozoic era, was due, 
as has been shown, to an actual sinking of the earth’s crust 
through lateral pressure, and not to local contraction in the 
strata themselves or the terranes underneath. But such a sub- 
sidence is not possible, unless seven miles—that is, seven miles 
in maximum depth and over a hundred in total breadth—unless 
seven miles of something were removed, in its progress, from 
the region beneath. 

If the matter beneath was not aérial, then liquid or viscous 
rock was pushed aside. This being a fact, it would follow that 
there existed, underneath a crust of unascertained thickness, a 
sea or lake of mobile (viscous or plastic) rock, as large as the 
sinking region; and also that this great viscous sea continued 
in existence through the whole period of subsidence, or, in the 
ease of the Alleghany region, through all Paleozoic time—an era 
estimated on a previous page to cover at least thirty-five millions 
of years, if time since the Silurian age began embraced fifty 
milhons of years. 

‘‘The facts thus sustain the statement that lateral pressure 
produced not only the subsidence of the Appalachian region 
through the Paleozoic, but also, cotemporaneously, and as its 
essential prerequisite, the rising of a sea-border elevation, or 
geanticlinal, parallel with it; and that both movements demanded 
the existence beneath of a great sea of mobile rock.’’ 


Am. Jour. Sct.—FourtH SrERrEs, Vout. XLVI, No. 271.—Juty, 1918. 


162 Barrell—Growth of Knowledge of Earth Structure. 


The recognition of regional warping as a major factor 
in the larger structure of mountain systems, and the 
expression of that factor in the terms geosyncline and 
geanticline forms a notable advance in geologic thought. 
Subsequent folding on a regional scale results in the 
development of synclinoria and anticlinoria. Van Hise 
has given these latter terms wide currency, but appar- 
ently inadvertently has used synclinorium in a different 
sense than that in which Dana defined it. Dana gave the 
word to a mountain range made by the mashing and up- 
lift of a geosyncline, Van Hise defines it as a downfold of 
a large order of magnitude, embracing anticlines and 
synclines within it; anticlinorium he uses for a corre- 
sponding up fold? Rice has called attention to this 
change of definition,!? but Van Hise’s usage is likely to 
prevail, since they are needed terms for the larger moun- 
tain structure and do not require a determination of the 
previous limits of upwarp and downwarp,—of original 
denudation and deposition. Furthermore, a geosyncline 
in mountain folding may have one side uplifted, the other 
side depressed and there are reasons for regarding the 
folds of Pennsylvania, Dana’s type synclinorium, as 
representing but the western and downfolded side of the 
Paleozoic geosyncline. Under that view the folded 
Appalachians of Pennsylvania constitute a synclinormm 
in both the sense of Dana and Van Hise. 


The Ultimate Cause of Crustal Compression. 


The next important advance in the theory of moun- 
tains was made by C. E. Dutton who in 1874 published in 
the Journal (8, 113-123) an article entitled ‘‘A criticism 
upon the contractional hypothesis.’’ Dutton gives rea- 
sons for holding that the amount of folding and shorten- 
ing exhibited in mountain ranges, especially those of 
Tertiary date, is very much greater in magnitude and is 
different in nature and distribution from that which 
would be given by the surficial cooling of the globe. The 
following quotations cover the principal points in the 
argument : 

2 ©, R. Van Hise, Principles of North American Pre-Cambrian Geology, 
U. S. Geol. Surv., 16th Ann. Report, pt. I, pp. 607-612, 1896. 


18 W. N. Rice, On the use of the words synclinorium and anticlinorium, 
Science, 23, 286, 287, 1906. 


Barrell—Growth of Knowledge of Earth Structure. 163 


““The argument for the contractional hypothesis presupposes 
that the earth-mass may be considered as consisting of two por- 
tions, a cooled exterior of undetermined (though probably com- 
paratively small) depth, inclosing a hot nucleus. . . . The 
secular loss of heat, it is assumed, would be greater from the 
hot nucleus than from the exterior, and the greater consequent 
contraction of the nucleus would therefore gradually withdraw 
the support of the exterior, which would collapse. The result- 
ing strains upon the exterior would be mainly tangential. 
Owing to considerable inequalities in the ability of different por- 
tions to resist the strains thus developed, the yielding would take 
place at the lines, or regions of least resistance, and the effects 
of the yielding would be manifested chiefly, or wholly, at those 
places, in the form of mountain chains, or belts of table-lands, 
and in the disturbanees of stratification. The primary division 
of the surface into areas of land and water are attributed to the 
assumed smaller conductivity of materials underlying the land, 
which have been left behind in the general convergence of the 
surface toward the center. Regarding these as the main and 
underlying premises of the contractional argument, it is con- 
sidered unnecessary to state the various subsidiary propositions 
which have been advanced to explain the determination of this 
action to particular phenomena, since the main proposition upon 
which they are based is considered untenable. 

There can be no reasonable doubt that the earth-mass consists 
of a cooled exterior inclosing a hot nucleus, and a necessary 
corollary to this must be secular cooling, probably accompanied 
by contraction of the cooling portions. But when we apply the 
known laws of thermal physics to ascertain the rate of this 
cooling, and its distribution through the mass, the objectionable 
character of the contractional hypothesis becomes obvious. 

That Fourier’s theorem, under the general conditions given, 

expresses the normal law of cooling, is admitted by all mathe- 
maticians who have examined it. The only ground of contro- 
versy must: be upon the values to be assigned to the constants. 
But there seem to be no values consistent with probability which 
can be of help to the contractional hypothesis. The applica- 
tion of the theorem shows that below 200 or 300 miles the cool- 
ing has, up to the present time, been extremely little. 
At present, however, the unavoidable deduction from this 
theorem is that the greatest possible contraction due to secular 
cooling is insufficient in amount to account for the phenomena 
attributed to it by the contractional hypothesis. 

The determination of plications to particular localities pre- 
sents difficulties in the way of the contractional hypothesis which 
have been underrated. It has been assumed that if a contraction 
of the interior were to occur, the yielding of the outer crust 
would take place at localities of least resistance. But this could 


164 Barrell—Growth of Knowledge of Earth Structure. 


be true only on the assumption that the crust could have a hori- 
zontal movement in which the nucleus does not necessarily share. 
A vertical section through the Appalachian region and west- 
ward to the 100th meridian shows a surface highly disturbed 
for about two hundred and fifty miles, and comparatively undis- 
turbed for more than a thousand. No one would seriously argue 
that the contraction of the nucleus had been confined to portions 
underlying the disturbed regions: yet if the contraction was 
general, there must have been a large amount of slip of some 
portion of the undisturbed segment over the nucleus. Such a 
proposition would be very difficult to defend, even if the pre- 
mises were granted. It seems as if the friction and adhesion of 
the crust upon the nucleus had been overlooked. Nor could this 
be small, even though the crust rested upon liquid lava. ‘The 
attempts which some eminent geologists have recently made to 
explain surface corrugation by this method clearly show a neeg- 
lect on their part to analyze carefully the system of forces which 
a contraction of the nucleus would generate in the crust. Their 
discussions have been argumentative and not analytical. The 
latter method of examination would have shown them certain 
difficulties irreconcilable with their knowledge of facts. Adopt- 
ing the argumentative mode, and in conformity with their view 
regarding the exterior as a shell of insufficient coherence to 
sustain itself when its support is sensibly diminished, the ten- 
deney of corrugation to occur mainly along certain belts, with 
series of parallel folds, is not explained by assuming that these 
localities are regions of weakness. For a shrinkage of the 
nucleus would throw each elementary portion of the crust into 
a state of strain by the action of forces in all directions within 
its own tangent plane. A relief by a horizontal yielding in one 
direction would by no means be a general relief.’’ 


Dutton’s criticisms robbed the current hypothesis of 
mountain-making of its conventional basis without pro- 
viding a new foundation. It was a quarter of a cen- 
tury in advance of its time, has been seldom cited, and 
seems to have had but little direct influence in shaping 
subsequent thought. It, however, gave direction to Dut- 
ton’s views, and his later papers were far-reaching in 
their influence. 

If contraction from external cooling is not the cause 
of the compressive forces it is necessary to seek another 
cause. Two years later, in 1876, Dutton attempted to 
provide an answer to this open question.‘* <A review of 
this paper, evidently by J. D. Dana, 1s given in the Jour- 
nal. The following explanations of Dutton’s theory and 


140, E. Dutton, Critical observations on theories of the earth’s physical 
evolution, The Penn Monthly, May and June, 1876. 


Barrell—Growth of Knowledge of Earth Structure. 165 


of Dana’s comments upon it are contained in a few para- 
eraphs from this review (12, 142, 1876). 


‘*Captain Dutton presents in this paper the views brought out 
in his article in volume viii of this Journal, with fuller illustra- 
tions, and adds explanations of his theory of the origin of moun- 
tains. The discussion should be read by all desiring to reach 
right conclusions, it presenting many arguments from physical 
considerations against the contraction-theory, or that of the 
uplifting and folding of strata through lateral pressure. There 
is much to be learned before any theory of mountain-making 
shall have a sufficient foundation in observed facts to demand 
full confidence, and Captain Dutton merits the thanks of geolo- 
gists for the aid he has given them toward reaching right con- 
clusions. His discussions are not free from misunderstandings 
of geological facts, and if they fail to be finally received it will 
be for this reason. 

We here give in a brief form, and nearly in his own words, 
the principal points in his theory of mountain-making as 
explained in the later part of his memoir. 

Accepting the proposition that there is a plastic condition of 
rock beneath the earth’s crust and that metamorphism is a 
‘hydrothermal process,’ and believing that ‘the penetration of 
water to profound depths [in the earth’s crust] is a well sus- 
tained theory,’ he says that great pressure and a temperature 
approaching redness are essential conditions of metamorphism. 

‘The heaviest portion would sink into the lighter colloid 
mass underneath, protruding it laterally beneath the lighter 
portions where, by its lighter density, it tends to accumulate.’ 
He adds: ‘The resulting movements would be determined, first, 
by the amount of difference in the densities of the upper and 
lower masses, and, second, by inequalities in the thickness of 
the strata: the forces now become adequate to the building of 
mountains and the plication of strata, and their modes of opera- 
tion agree with the classes of facts already set forth as the 
concomitants of those features.’ 

The views are next applied to a system of plications. ‘It has 
been indicated that plications occur where strata have rapidly 
accumulated in great volume and in elongated narrow belts; 
that the axes of plications are parallel to the axes of maximum 
deposit; and that the movements immediately followed the 
deposition ’—the case of the Appalachians being an example in 
which the accumulations averaged 40,000 feet. He observes: 
“Wherever the load of sediments becomes heaviest, there they 
sink deepest, protruding the colloid magma beneath them to the 
adjoining areas, which are less heavily weighted, forming at 
once both synclinals and anticlinals.’ 

With regard to this new theory, we might reasonably question 
the existence of the colloid magma—a condition fundamental to 


166 Barrell—Growth of Knowledge of Earth Structure. 


the theory—and his evidence that water penetrates to profound 
depths in the earth’s crust sufficient to make hydrous rocks. 
We might ask for evidence that the rocks beneath the Cretaceous 
and Tertiary. and other underlying strata of the Uintahs, were 
in such a colloid state, and this so near the surface, that the 
‘beds subsided by their gross weight as rapidly as they grew.’ 
Again, he says that the movements of mountain-making 
‘immediately followed the deposition.’ ‘Immediately’ sounds 
quick to one who appreciates the slowness of geological changes. 
The Carboniferous age was very long; and somewhere in that 
part of geological time, either before the age had fully ended, 
or some time after its close, the epoch of catastrophe began.’’ 


We see foreshadowed in this paper the theory of 
isostasy, or condition of vertical equilibrium in the crust 
which Dutton published in 1889. This theory has borne 
remarkable fruit, but Dutton attempted to link to it the 
horizontally compressive forces which have produced 
folding and overthrusting. Willis in 1907'° and Hayford 
in 1911, overlooking Dana’s objections, have attempted 
to make a lateral isostatic undertow the cause of all hori- 
zontal movements in the crust, adopting the mechanism 
of Dutton. The present writer, although accepting the 
principle of isostasy as an explanation of broad vertical 
movements, has published papers which go to show the 
inadequacy of this hypothesis of lateral pressure; inade- 
quate in time relation, in amount, and in expression.'® 

In 1903 it was determined by several physicists that 
the materials of the earth’s crust were radioactive and 
must generate throughout geologic time a quantity of 
heat which perhaps equalled that lost by radiation into 
space. By 1907 this had become demonstrated. The 
remarkable conclusion had been reached that the earth, 
although losing heat, is not a cooling globe. Dut- 
ton’s contentions against mountain growth through 
external cooling and contraction were thus unexpectedly, 
through a wholly new branch of knowledge, demonstrated 
to be true. 

Nevertheless, all students of orogeny are agreed that 
profound compressive forces have been the chief agents 
in developing mountain structures. Chamberlin was 
the first to arrive at the idea that the shrinkage may 
originate in the deeper portions of the earth under the 


1 B. Willis, Research in China, vol. 2, 1907. 
16 Joseph Barrell, Science, 39, 259, 260, 1909; Jour. Geol., 22, 672-683, 
1914. : 


Barrell—Growth of Knowledge of Earth Structure. 167 


urgency of the enormous pressures, apparently by giving 
rise to slow recombinations of matter into denser 
forms.!* 


The New Era in the Interpretation of Mowntan Structures. 


In the meantime, between 1874 and 1904, another 
advance in the knowledge of mountain structures was 
taking place in Kurope. Suess studied the distribution 
of mountain ares over the earth and dwelt upon the 
prevalence of overthrust structures; the backland being 
thrust toward and over the foreland, the rise of the 
mountain are or geanticline depressing the foredeep or 
geosyncline. Bertrand and Lugeon from 1884 to 1900 
were reinterpreting the Alpine structures on this basis. 
They showed that the whole mountain system had been 
overturned and overthrust from the south to an almost 
incredible degree. HKnormous denudation had later dis- 
severed the northern outlying portions and given rise to 
‘‘mountains without roots,’’—isolated outhers, consist- 
ing of overturned masses of strata which had accumu- 
lated as sediments far to the southward in another por- 
tion of the ancient geosyncline. 

On a smaller scale similar phenomena are exhibited in 
the Appalachians. Willis showed that the deep subsi- 
dence of the center of the geosyncline gave an initial dip 
which determined the position of yielding under compres- 
sion. Laboratory experiments brought out the weakness 
of the stratigraphic structure to resist horizontal com- 
pression. The nature of the stratigraphic series was 
shown to determine whether the yielding would be by 
mashing, competent folding, or breakage and overthrust. 
The problem of mountain structures was thus brought 
into the realm of mechanics. These results were pub- 
lished in three sources in 1893,—the Transactions of the 
American Institute of Mining Engineers, the thirteenth 
annual report of the United States Geological Survey, 
and this Journal (46, 257, 1893). 

_ Finally should be noted the contributions of the Lake 
Superior school of geology, in which the work of Van 
Hise stands preéminent. Under the economic stimulus 
given by the discovery and development of enormously 
rich bodies of iron ore, hidden under Pleistocene drift 
and involved in the complex structures of vanished moun- 
“'T, C. Chamberlin, Geology, vol. 1, pp. 541, 542, 1904. 


168 Barrell—Growth of Knowledge of Earth Structure. 


tain systems of ancient date, structural geology and met- 
amorphism have become exact sciences to be drawn upon 
in the search for mineral wealth and yielding also rich 
returns in a fuller knowledge of early periods of earth 
history. 


Crust Movements as revealed by Physiography. 


During the last quarter of the nineteenth century 
another ‘division of geology, dominantly American, was 
taking form and growth,—the science of land forms,— 
physiography. The history of that development is 
treated by Gregory in the preceding chapter but some of 
its bearings upon theory, in so far as they affect the sub- 
ject of mountain origin, are necessarily given here. 

Powell, Dutton, and Gilbert in their explorations of the 
West saw the stupendous work of denudation which had 
been carried to completion again and again during the 
progress of geologic time. The mountain relief conse- 
quently may be much younger than the folding of the 
rocks, and may be largely or even wholly due to recurrent 
plateau movement, a doctrine to which Dana had pre- 
viously arrived. But the introduction of the idea of the 
peneplain opened up a new field for exploration in the 
nature and date of crustmovements. Davis by this means 
began to study the later chapters of Appalachian history, 
the most important early paper being published in 1891.** 
Sinee then Davis, Willis, and many others have found 
that, girdling the world, a large part of the mountainous 
relief is due to vertical elevatory forces acting over 
regions of previous folding and overthrust. In addition, 
eréat plateau areas of unfolded rocks have been bodily 
lifted one to two miles, or more, above their earlier levels. 
They may be broad geanticlinal arches or bounded by the 
walls of profound fractures. 

The linear mountain systems made from deep troughs 
of sediments have come then to be recognized as but one 
of several classes of mountains. This class, from its 
clear development in the Appalachians, and the fact that 
many of the laws of mountain structure pertaining to it 
were first worked out there, has been called by Powell the 
Appalachian type (12, 414, 1876). A classification of 


1 W. M. Davis, The geological dates of origin of certain pee. 
forms on the Atlantic slope of the United States, Geol. Soe. Am. Bull., 
541-542, 545-586, 1891. 


Barrell—Growth of Knowledge of Earth Structure. 169 


mountain systems was proposed by him in which moun- 
tains are classified into two major divisions, those com- 
posed of sedimentary strata altered or unaltered, and 
those composed in whole or in part of extravasated mate- 
rial. The first class he subdivides into six sub-classes 
of which the folded Appalachians illustrate one. It 
appears to the writer that Powell’s classification gives 
disproportionate importance to certain types which he 
deseribed; but nevertheless, the fact that such a classi- 
fication was made, indicates the growth of a more com- 
prehensive knowledge of mountains,—their origin, struc- 
ture, and history. 


Relations of Crust Movements to Density and Equilibrium. 


A recent important development in the fields of geo- 
physics and major crust movements consists in the incor- 
poration into geology of the doctrine of isostasy. The 
evidence was developed in the middle of the nineteenth 
century by the geodetic survey of India which indicated 
that the Himalayas did not exert the gravitative influence 
that their volume called for. It was clear that the crust 
beneath that mountain system was less dense than 
beneath the plains of India and still less dense than the 
crust beneath the Indian Ocean. This relation between 
density and elevation indicated some approach to flota- 
tional equilibrium in the crust, comparable in its nature 
though not in delicacy of adjustment to the elevation of 
the surface of an iceberg above the ocean level owing to 
its depth and its density, less than that of the surround- 
ing medium. This important geological conception was 
kept within the confines of astronomy and geodesy, how- 
ever, until Dutton in 1876, but especially in 1889, brought 
it into the geologic field. A test of isostasy was made for 
the United States by Putnam and Gilbert in 1895 and 
much more elaborate investigations have since been made 
by Hayford and Bowie. These investigations demon- 
strate the importance and reality of broad warping 
forees acting vertically and related to the regional varia- 
tions of density in the crust. 

There are consequently two major and unrelated 
classes of forces involved in the making of mountain 
structures,—the irresistible horizontal compressive 
forces, arising apparently from condensation deep within 
the earth, and vertical forces originating in the outer 


170 Barrell—Growth of Knowledge of Earth Structure. 


envelopes and tending toward a hydrostatic equilibrium. 
In this latter field of investigation, America, since the 
initial paper by Dutton, has taken the lead. 


Conclusion on Contributions of America to Theories of Orogeny. 


The sciences arose in Europe, but those which treated 
of the earth were still in their infancy when transplanted 
to America. The first comprehensive ideas on the nature 
of mountain structures arose in Great Britain and 
France. These ideas served as a guide and stimulus to 
observation in the recognition of deformations in the 
strata of the Appalachian system. Since 1840, however, 
America has ceased to be a pupil in this field of research 
but has joimed as an equal with the two older countries. 
New ideas have been contributed, new and striking illus- 
trations cited first by the scientists of one nation, next by 
those of another. The composite mass of knowledge has 
erown as a common possession. Nevertheless, a review 
of the progress since 1840 as measured by the contribu- 
tion of new ideas shows on the whole America at least 
equal to its intellectual rivals, and at certain times 
actually the leader. This is true of the science of geol- 
ogy as a whole and also of the subdivision of orogeny. 

Thus far no mention has been made of German geolo- 
gists, with the exception of Suess, an Austrian. German 
geology is voluminous and the names of many well-known 
geologists could be cited. But this article has sought 
to trace the origin and growth of fundamental ideas. 
The Germans have been assiduous observers of detail; 
preéminent as systematizers and classifiers, seldom orig- 
inators. Even petrology, which might be regarded as 
their especial field, was transplanted from Great Britain. 
In the science of mountains they have followed in their 
fundamental ideas especially the French. 

Turning to the mediums of publication through which 
this progress of knowledge in earth structures has been 
recorded, the American Journal of Science stands fore- 
most as the only continuous record for the whole century 
in American literature, fulfilling for this country what the 
Quarterly Journal of the Geological Society has done for 
Great Britain since 1845, and the Bulletin de la Société 
Géologique for France since 1830. 


G. O. Snuth—Government Geological Surveys. 171 


Art. V.—A Century of Government Geological Surveys; 
by Grorce Oris SmitH, Director of the United States 
Geological Survey. 


Even a Federal bureau must be considered a product 
of evolution: the past of the United States Geological 
Survey far antedates March 3, 1879. The scope of 
endeavor, the refinement of method, and especially the 
personnel of the newly created service of that day were 
largely inherited from pioneer organizations. There- 
fore a review of the country’s record of surveys under 
Government auspices becomes more than a grateful 
acknowledgment by the present generation of geologists 
of the credit due to those who blazed the way; it shows 
the sequence and progress in the contributions made by 
geologic science to industry. 

The earlier stages in industrial evolution mentioned by 
Hess'—exploitation, development, and maturity—deter- 
mine a somewhat similar progressive development in 
geologic investigation, so that geographic exploration 
and geologic reconnaissance of the broadest type are the 
normal contribution of exact science whenever and 
wherever a nation isin the state of exploitation and 
initial development of its mineral and agricultural 
resources. The refinements of detailed surveys and 
quantitative examinations belong rather to the next stage 
of intensive utilization, or, indeed, they are the essentials 
preliminary to fulluse. Thus regrets that the results of 
present-day work were not available fifty years ago are 
largely vain: the fathers may not have been without the 
vision; they simply did the work as their day and gener- 
ation needed it done. 

‘Twenty years ago S. F. Emmons, in a presidential 
address before the Geological Society of Washington, 
divided the history of Governmental surveys in this 
country into two periods, separated in a general way by 
the Civit War. The first of these was the period of geo- 
graphic exploration, the second that of geologic explora- 
tion. Mr. Emmons of course regarded this subdivision 
as not hard and fast, yet his dividing line seems logical, 
for not only did the military activities in the Hast neces- 
sarily suspend exploration in the West, but after the war 

* Hess, R. H., Foundations of National Prosperity, p. 100. 


172 G.O. Smith—Government Geological Surveys. 


national, political, and economic considerations led nat- 
urally to the demand for a more exact knowledge of the 
vast national domain in the West. Geography and geol- 
ogy are so closely related that Mr. Emmons’s distinction 
of the two periods is useful only with the limitations 
inferentially set by himself—namely, that while geologic 
investigation entered into most of the explorations of the 
earlier period, the geologist was regarded as only an 
~ accessory in these exploring expeditions; on the other 
hand, in the later surveys the topographic work was 
developed because it was essential to the geologic 
investigations. 

The year 1818 was a notable one in American geology, 
first of all in the appearance of the American Journal of 
Science, itself so perfect a vehicle for geological thought 
that, as is so well stated by Dr. G. P. Merrill, ‘‘a perusal 
of the numbers from the date of issue down to the present, 
time will alone afford a fair idea of the gradual progress 
of American geology.’’ The beginning of publications 
on New England geology appeared that year in Kidward 
Hitcheock’s first paper on the Connecticut Valley (1, 105, 
1818) and the Danas’ (S. L. and J. F.) detailed geologic 
and mineralogic description of Boston and vicinity; and 
the ‘‘Index’’ of Amos Haton (noticed in this Journal, 1, 
69) was the first of that long list of notable contributions 
to American stratigraphy that are to be credited to the 
New York geologists. 

Tn the present discussion, too, the year 1918 can be 
regarded as in a way the centennial of Government geo- 
logic surveys, for it was in 1818 that Henry R. School- 
craft began his trip to the Mississippi Valley—perhaps 
the first geologic reconnaissance into the West—and it 
was his work in the lead region which served to make him 
a member of the Cass expedition sent out by the Secre- 
tary of War in 1820 to examine the metallic wealth of the 
Lake Superior region. The earlier Government explora- 
tions of Lewis and Clark, in 1803-7, and of Pike, in 1805-7, 
were so exclusively geographic that geologic work under 
Federal auspices must be regarded as beginning with 
Schoolcraft and with Edwin James, the geologist of the 
expedition of Major Long in 1819-20 to the Rocky Moun- 
tains. Both these observers published reports that are 
valuable as contributions to the knowledge of little- 
known regions. ; 


G. O. Smmth—Government Geological Surveys. 173 


Any description of geologic work under the Federal 
Government that included no reference to the State 
surveys would be inadequate, for in both date of 
execution and stage of development the work of the State 
geologists must be given precedence. In Merrill’s Con- 
tributions to the History of American Geology,” whose 
modest title fails even to suggest that this work not only 
furnishes the most useful chronologic record of the 
progress of the science on the American continent but is 
in fact a very thesaurus of incidents touching the per- 
sonal side of geology, the author by his division of his 
subject shows that four decades of the era of State sur- 
veys elapsed before the era of national surveys began. 

Thus the geologic surveys of some of the Eastern 
States antedate by several decades any Federal organ- 
ization of comparable geologic scope, and in investiga- 
tions directed to local utilitarian problems these pioneer 
geologists working in the older settled States of the 
East were in fact already conducting work as detailed in 
type as much of that attempted by the Federal geologists 
of the later period. Even to-day it is true in a general 
way that the State geologist can and should attack many 
of his local problems with intensive methods and with 
detail of results that are neither practicable nor desirable 
for the larger interstate investigations or for examina- 
tions in newer territory. All this relation of State and 
Federal work must be looked upon as normal evolution- 
ary development of geologic science in America. 

One who reads the names of the Federal geologists of 
the early days, beginning with Jackson and Owen and 
following with such leaders in Federal work as Gilbert, 
Chamberlin, King, R. D. Irving, Pumpelly, Van Hise, 
and Walcott, may note that these were all connected in 
their earlier work with State surveys. Nor has the rela- 
tion been one-sided, for among the State geologists 
Whitney, Blake, Mather, Newberry, J. G. Norwood, Pur- 
due, Bain, Gregory, Ashley, Kirk, W. H. Emmons, 
DeWolf, Mathews, Brown, Landes, ‘Moore, and. Orider 
received their field tr aining in part or wholly as members 
of a-Federal Survey. Mor eover, under the present plan 
of effective codperation of several of the State surveys 
with the United States Geological Survey, it is often dif- 
ficult te differentiate between the two in either personnel 

? Report Nat’] Museum, 1904, pp. 189-733. 


174 G.O. Smith—Government Geological Surveys. 


or results, for it even happens that the publishing organ- 
ization may not have been the major contributor. The 
full record of American geology, past and present, can 
not be set forth in terms of Federal auspices alone. 

The three decades preceding the Civil War, then, con- 
stitute the era of State surveys, well described by Mer- 
rill as at first characterized by a contagious enthusiasm 
for beginning geologic work, later by a more normal 
condition m which every available geologist seems to 
have been quietly at work, and finally by renewed activity 
in creating new organizations. The net result was that 
Louisiana and Oregon seem to have been the only States 
not having at least one geological survey. 

The first specific appropriation by the Federal Govern- 
ment for geologic investigation appears to have been 
made in 1834, when a supplemental appropriation for 
surveys of roads and canals under the War Department, 
authorized in 1824, contained the item ‘‘of which sum 
five thousand dollars shall be appropriated and applied 
to geological and mineralogical survey and researches.’’ 
In July, 1834, Mr. G. W. Featherstonhaugh was appointed 
United States geologist and employed under Colonel 
Abert, U. S. Topographical Engineers, to ‘‘personally 
inspect the mineral and geological character’’ of the pub- 
lie lands of the Ozark Mountain region. Overlooking 
the incidental fact that this Englishman—a man of 
scientific attainment and large interest in public affairs— 
was never naturalized,* it must be placed to the credit of 
this first of United States geologists that within seven 
months he completed his field work and returned to 
Washington, and on February 17, 1835, his report was 
transmitted to Congress. Two years earlier Feather- 
stonhaugh had memorialized Congress for aid im the 
preparation of a geologic map of the whole territory of 
the United States, and in connection with this project he 
suggested that geology as an aid to military engineering 
should have a place in the curriculum at West Point. 
This first United States geologist also appears to have 
combined an appreciation of the practical worth of ‘‘the 
mineral riches of our country, their quality, quantity, 
and the facility of procuring them,’’ with an interest 
the more scientific side of geology, though his hypotheses 
regarding both economic geology and stratigraphic and 

® Featherstonhaugh, J. D., Am. Geol., 3, 220, 1889. 


G. O. Snuth—Government Geological Surveys. 175 


structural geology have not won the endorsement of all 
later workers in the same regions. In all these respects, 
however, Featherstonhaugh may stand as a fairly good 
prototype. His contributions to international affairs 
subsequent to his scientific service to the United States 
are of interest; he served as one of Her Majesty’s com- 
missioners in the settlement of the Canadian-United 
States boundary question in 1839-40 and made an exam- 
ination of the disputed area, and after the settlement of 
this controversy he was appointed British Consul for the 
Department of the Seine, France, where in 1848 he per- 
sonally engineered the escape of Louis Philippe from 
Havre. 

The Federal geologic work thus started was soon con- 
tinued in surveys of wider scope and more thorough 
accomplishment. ‘The position of the Government as the 
proprietor of mineral lands in the Upper Mississippi 
Valley led to their examination. These Government 
lands containing lead had been reserved from sale for 
lease since 1807, although no leases were issued until 1822. 
The amount of illegal entry and consequent refusal of 
smelters and miners to pay royalty after 1834 forced the 
issue upon the attention of Congress, and in 1839 Presi- 
dent Van Buren was requested to present to Congress a 
plan for the sale of the public mineral lands. In carrying 
out this policy Dr. David Dale Owen was selected to 
make the necessary survey. 

Owen had served as an assistant on the State Survey 
of Tennessee and as the first State geologist of Indiana, 
and he organized the new work promptly and effectively. 
Although suffering from the handicap unfortunately 
known by geologists of the present day—the receipt late 
in the season (August 17, 1839) of authority to begin 
work—within exactly a month he had his force of 139 
assistants organized into 24 field parties, instructed in 
‘such elementary principles of geology as were neces- 
sary to their performance of the duties required of 
them.’’? His plan of campaign provided for a northward 
drive at a predetermined rate of traverse for each party, 
with periodic reports to himself at appointed stations, 
“‘to receive which reports and to examine the country in 
person’’ he crossed the area under survey eleven times. 
The result of such masterful leadership was the comple- 
tion of the exploration of all the lands comprehended in 


176 GG. O. Siuth—Government Geological Surveys. 


his orders in two months and six days, and his report on 
this great area—about 11,000 square miles—bears date 
of April 2, 1840. 

Hight years later Doctor Owen made a survey of an 
even larger area, continuing his examination northward 
to Lake Superior. Again his report was published 
promptly, and he continued for several years his exam- 
ination of the Northwest Territory, submitting his final 
report in 1851. It is interesting to note that in his 
earlier report Doctor Owen subscribed himself as ‘‘ Prin- 
cipal Agent to explore the Mineral Lands of the United 
States,’’ but that in the later report he was ‘‘U. S. Geolo- 
gist for Wisconsin.’’ The two surveys together covered, 
07,000 square miles. 

During the same period similar surveys were being 
made in northern Michigan by Dr. Charles T. Jackson, 
1847-48, and Foster and Whitney, 1849-51. These sur- 
veys also had been hastened by the ‘‘copper fever’’ of 
1844-46, with wholesale issue of permits and leases, Con- 
gress in 1847 authorizing the sale of the mineral lands 
and a geological survey of the Lake Superior district. 
The execution of these surveys under Jackson and under 
Foster and Whitney and the prompt publication in 1851 
of the maps of-the whole region materially helped to 
establish copper mining on a more conservative basis, 
and the development of the Lake Superior region 
was rapid.* 

These land-classification surveys, with their definite 
purpose, represent the best geologic work of the time. 
The plan necessitated thoroughgoing field work with con- 
siderable detail and prompt publication of systematic 
reports, and in the working up of the results specialists 
like James Hall and Joseph Leidy contributed, while 
F. B. Meek was an assistant of Owen. It is worthy of 
note that had not Doctor Houghton, the State geologist of 
Michigan, met an untimely death in 1847, effective coop- 
eration of the State Survey with the Federal officials 
would have combined geologic investigation with the 
execution of the linear surveys.°® 

Belonging to the same period of geologic exploration 
was the service of J. D. Dana, as United States Geologist 


Whitney, Mineral Wealth of the United States, pp. 248-250. 
5 Foster and Whitney, 31st Cong., lst session, House Doc. 69, pp. 13-14, 
1850. 


G. O. Smith—Government Geological Surveys. 117 


on the Wilkes Exploring Expedition, the disaster to 
which compelled his return from the Pacific Coast over- 
land and resulted in his geologic observations on Oregon 
and northern California. | 

The military expeditions during the decade 1850-60 
and the earlier expeditions of Frémont added to the 
geographic knowledge of the Western country and also 
contributed to geologic science, largely through collec- 
tions of rocks and fossils, usually reported on by the 
specialists of the day. Thus the names of Hall, Con- 
rad, Hitchcock, and Meek appear in the published 
reports on these explorations, while Marcou, Blake, 
Newberry, Gibbs, Evans, Hayden, Parry, Shumard, 
Schiel, Antisell, and Engelmann were geologists attached 
to the field expeditions. In 1852 geologic investigation 
was seemingly so popular as to necessitate the statutory 
prohibition ‘‘there shall be no further geological survey 
by the Government unless hereafter authorized by law.’’ 

Certain of these explorations had a specific pur- 
pose: several of them sought a practical route for 
a transcontinental railroad; another a new wagon 
road across Utah and Nevada; and one under 
Colonel Pope, with G. G. Shumard as geologist, was 
sent out ‘‘for boring Artesian Wells along the line 
of the 32d Parallel’? in New Mexico. The pub- 
lished reports varied greatly in scientific value and in 
cearefulness of preparation, while the publication of at 
least two reports was delayed until long after the war, 
and the manuscript of another was lost. The report of 
the expedition of Major Emory contained a colored 
geologic map of the western half of the country, a pioneer 
publication, for the map prepared by Marcou extended 
only to the 106th meridian. 

Thus in the first period of Government surveys, cover- 
ing about forty years, the great West, with its wealth of 
public lands, was well traversed by exploratory surveys, 
which furnished, however, only general outlines for a 
comprehension of the stratigraphy and structure of 
mountain and valley, plain and plateau. ‘To an even less 
degree was there any realization of the economic possi- 
bilities of the vast territory west of the Mississippi. 
President Jefferson, in planning the Lewis and Clark 
expedition, had stated his special interest in the mineral 
resources of the region to be traversed. Nearly forty 


178) G. O. Smuth—Government Geological Surveys. 


years later Doctor Owen was strongly impressed with — 
the commercial promise of the region he surveyed. His 
reports contain analyses of ores and statistics of produc- 
tion; he compared the lead output of Wisconsin, Iowa, 
and Illinois with that of Europe and foretold the value 
of the iron, copper, and zine deposits of the area; he 
outlined the extent of the Illinois coal field; and he laid 
equal emphasis upon the agricultural possibilities of the 
region. Indeed, so optimistic were Owen’s general con- 
clusions that he referred to his separate township plats, 
with their detailed descriptions, as the basis for his san- 
guine opinions, realizing that ‘‘the explorer is apt to 
become the special pleader.’’ With equal breadth of 
view and thoroughness of execution the surveys of Fos- 
ter and Whitney laid the foundation for the development 
of the copper and iron resources of the Lake Superior 
region, and although these areas were largely wilderness 
and not adapted to rapid traverse or easy observation 
the reports on their explorations nevertheless compare 
most favorably with the contributions of geologists work- 
ing in the more hospitable regions in the older States. 

The period following the Civil War naturally became 
one of national expansion, the faces of many were turned 
westward, and exploration of the national domain for its 
industrial possibilities took on fresh interest. Home- 
seekers and miners largely made up this army of peace- 
ful invasion, and the winning of the West began on a 
scale quite different from that of the days of the military 
path-finding expeditions of Frémont and other Army 
officers. Thus the nation was aroused to the task of 
investigating its public lands and Congress gave the sup- 
port needed to make geologic exploration possible on a 
large seale. 

Geologie surveys of a high order were continued 
in the older States, as shown by the contributions 
during this period of J. P. Lesley and G. H. Cook in 
the Hast, W. C. Kerr, KH. W. Hilgardjeande gee 
Smith: in: the South; and-J. S. Newbemogea@ines: 
White, Raphael Pumpelly, T. C. Chamberlin, Alex- 
ander Winchell, and T. B. Brooks in the Central States. 
To the north the Canadian Survey, organized in 1841 
under Logan, had continued under the same sturdy 
leadership until 1869, when the experienced and talented 
Doctor Selwyn became Director. As contrasted with the 


G. O. Smith—Government Geological Surveys. 179 


short careers of most of the State Surveys and with the 
temporary character of all of the Federal undertakings 
in geologic investigation, the continuance of the Cana- 
dian Geological Survey for more than half a century 
under two directors gave opportunity for continuity of 
effort in making known to the people of the Dominion its 
resources and at the same time contributing to the world 
much pure science. | 

Passing with simple mention the two Government expe- 
ditions into the Black Hills, which afforded opportunity 
for geologic exploration by N. H. Winchell in 1874 and by 
Jenney and Newton in 1875, the record of geologic work 
under Government auspices in the period immediately 
following the Civil War groups itself around the names 
of four leaders—Hayden, King, Powell, and Wheeler. 
The four organizations, distinguished commonly by the 
names of these four masterful organizers, occupied the 
Western field more or less continuously from 1867 to 1878, 
and the sum total of their contributions to geography 
and geology was large indeed. In the words of Clarence 
King,® ‘‘Kighteen hundred and sixty-seven, therefore, 
marks, in the history of national geological work, a turn- 
ing point, when the science ceased to be dragged in the 
dust of rapid exploration and took a commanding posi- 
tion in the professional work of the country.’’ Together 
these four expeditions covered half a million square 
miles, or more than a third of the area of the United 
States west of the one-hundredth meridian, and the cost 
of all this work was approximately two million dollars, 
which was a small fraction of its value to the nation 
counting only the impetus given to settlement and utili- 
zation. : 

As viewed from a distance of nearly half a century, 
these four surveys differed much in plan of organization, 
scope of purpose, and success of execution, so that com- 
parison would have little value except as possibly bear- 
ing upon the work of the larger organization which 
followed them and became the heir not only to much that 
had been attained by these pioneer surveys but also to 
the great task uncompleted by them. So, if in the 
earliest days of the present United States Geological 
Survey there may have been a certain partisanship in 
tracing derived characters in the new organization, it is 

° First Annual Rept. U. S. Geol. Survey, p. 4. 


180 G. O. Smith—Government Geological Surveys. 


even now worth while to recognize the real origin of 
much that is credited to present-day development. 

Dr. F. V. Hayden was the first of these Survey leaders 
to engage in geological exploration. He visited the Bad- 
lands as early as 1853, and his connection with subse- 
quent expeditions was interrupted only by his service as 
a surgeon in the Federal Army during the war. In 1867, 
however, Hayden resumed his geologic work as United 
States Geologist in Nebraska, operating under direction 
of the Commissioner of the General Land Office. In the 
following eleven years the activities of the Hayden Sur- 
vey—the ‘‘Geological and Geographical Survey of the 
Territories’’—extended into Wyoming, Colorado, New 
Mexico, Montana, and Idaho, covering with areal sur- 
veys 107,000 square miles. This Survey, as might be 
expected from the long experience of its leader, made 
large contributions to stratigraphy, which involved 
notable paleontologic work by Cope, Meek, and Les- 
quereux. Next in importance was the structural work of 
A. C. Peale, W. H. Holmes, Capt. C. EK. Dutton, and Dr. 
Hayden himself, and the influence of these expeditions in 
popularizing geology should not be overlooked. The 
expedition of 1871 into the geyser region on the upper 
Yellowstone resulted in the creation of the first of the 
national parks. W. H. Holmes began his artistic contri- 
butions to geology in 1872 with this Survey. Topo- 
eraphic mapping was added to the geologic exploration, 
James T. Gardner and A. D. Wilson joming the Hayden 
Survey after earlier service on the King Survey and 
Henry Gannett being a member of parties, first as astron- 
omer and later as topographer in charge. The accom- 
plishment of the Hayden Survey itself and the later work 
of many of its members show that this organization pos- 
sessed a corps of strong men. 

The King Survey was a smaller .organization, with 
Congressional authorization of definite scope and a sys- 
tematic plan of operation. The beginning of construc- 
tion of the Union Pacific terminated the period of the 
railroad surveys under the War Department and 
afforded opportunity for geologic work that would be 
more than exploratory: the opening up of the new 
country made investigation of its resources logical. 
This fact was recognized by Clarence King, who had 
traversed the same route as a member of an emigrant 


G. O. Snuth—Government Geological Surveys. 181 


train with his friend James T. Gardner. His plan to 
make a geological cross section of the Cordilleras, with a 
study of the resources along the route of the Pacific rail- 
roads, won the support of Goner ess, and the ‘‘ Geological 
Exploration of the Fortieth Par allel’? was authorized in 
1867, with Clarence King as geologist in charge, under 
the Chief of Engineers of the Army. Field work was 
begun in the summer of that year, and it is interesting to 
note that Mr. King and his small force of geological 
assistants—the two Hagues and 8S. F. Emmons—began 
at the western end.of this cross section, and in this 
and subsequent years extended the survey from the east 
front of the Sierra Nevada to Cheyenne, covering a belt 
of territory about 100 miles in width. This comprehen- 
sive plan was carried out in the field operations, and the 
scientific and economic results were systematically 
worked up in the reports, which appeared in 1870-80. 
The only departure from this plan was a study of the 
voleanic mountains Shasta, Rainier, and Hood, in 1870, 
occasioned by an unexpected and unsolicited appropria- 
tion for field work, and that summer’s work resulted in 
the discovery of active glaciers, the first known within 
the United States. 

The Fortieth Parallel Survey is to be credited with 
contributions to the knowledge of the stratigraphy of the 
West, the region traversed being remarkably representa- 
tive of the stratigraphic column, to which was added the 
paleontologic work of Marsh, Meek, Hall, and Whitfield, 
while the attempt was made to interpret the sedimentary 
record in terms of Paleozoic, Mesozoic, and Tertiary 
geography. King’s plan of survey included large use of 
topographic mapping with astronomic base and triangu- 
lation control and contours based upon barometric eleva- 
tions. The results were pronounced by an unfriendly 
eritic’ as ‘‘very valuable, especially from a geological 
point of view,’’ but unfortunate in being the forerunner 
of work in wien Government geologists ‘‘have presumed 
to arrogate the control of the fundamental operations of 
a topographic survey.’’ To the King Survey must be 
credited the introduction of systematic contour mapping 
and the use of contour maps for purposes of geology. 
In two other respects the King Survey contributed 
largely to future Government work: microscopical 

* Wheeler, Report 3d Internat’l Geog. Cong., p. 492, 1885. 


182. G. O. Smith—Government Geological Surveys. 


petrography in the United States may be said to have 
begun with the visit of Professor Zirkel to this country as. 
a member of this Survey in 1875, and the report of J. D. 

Hague on ‘‘ Mining Industry’’ was the fitting expression 
of the emphasis then put on the study of the mineral 
resources of this newly opened territory, a subject of 
investigation that was in large part the true basis of 
King’s project rather than simply ‘‘the immediate 
excuse for the Survey.’’ An earlier influence in the sci- 
entific study of ore deposits had come from Von Richt- 
hofen’s investigation of the Comstock Lode in 1865 and 
his subsequent work with Whitney in California. The 
incident of King’s relation to the diamond fraud in Ari- 
zona in 1872 furnished a precedent for public servants of 
a later day; he investigated the reported find from scien- 
tific interest but exposed it with all the zeal of a publicist 
and truth lover. In a word, the Fortieth Parallel Sur- 
vey.commands our admiration for its brilliant plan, 
thoroughgoing work in field and office, and high quality 
of personnel. 

Major J. W. Powell began his large contribution to 
Government surveys with his exploration of the Grand 
Canyon in 1869, the Congressional recognition of his 
expedition being ‘limited to an authorization for the issue 
of rations by the War Department. Small appropria- 
tions were made in the following years, and in 1874 full 
authorization was given for the continuance of his survey 
in Utah under the Secretary of the Interior and was 
followed by the adoption of the name ‘‘United States 
Geographical and Geological Survey of the Rocky Moun- 
tain Region.’’ This organization was the least preten- 
tious of the four operating during this period—it covered 
less area, expended less public money, and published much 
less—but its contribution to American geology is not to be 
measured by miles or pages but by ideas. Its physical 
environment favored this survey, and in the work of 
Powell, Dutton, and Gilbert can be seen the beginnings of 
physiography on the heroic scale exemplified in the 
Grand Canyon and the High Plateaus. The first use of 
terms like ‘‘base level of erosion,’’ ‘‘consequent and 
antecedent drainage,’’ and ‘‘laccolith’’ marked the intro- 
duction of new ideas in the interpretation of land seulp- 
ture and geologic structure. The daring boat trip of 


G.O. Snuth—Government Geological Surveys. 188 


Powell was no less brilliant than his simple explanation 
of the Grand Canyon itself. 

‘‘The United States Geographical Surveys West of the 
100th Meridian’’ was the title given to the explorations 
made under Lieut. G. M. Wheeler, of the Engineer 
Corps, which began with topographic reconnaissances in 
Nevada, Utah, and Arizona, specifically authorized by 
Congress in 1872. From the standpoint of American 
ceology this could be better known as the Gilbert Survey, 
Mr. G. K. Gilbert serving for the three years 1871-73, the 
later part of the time with the title of chief geological 
assistant. Guilbert’s contributions included his descrip- 
tion of Basin Range structure, his first account of old 
Lake Bonneville, and his discussion of the erosion phe- 
nomena of the desert country. J. J. Stevenson also 
served later as a geologist of this Survey, and A. R. Mar- 
vine, E. E. Howell, E. D. Cope, Jules Marcou, and L. C. 
Russell were connected with the field parties. Captain 
Wheeler’s own claim for the work of his Survey empha- 
sized its geographic side, for he regarded the results as 
the partial completion of a systematic topographic sur- 
vey of the country. 

By 1878, when the Fortieth Parallel Survey had com- 
pleted the work planned by its chief, three of these inde- 
pendent surveys still contended for Federal support and 
for scientific occupation of the most attractive portions 
of the Western country. Unrestrained competition of 
this kind, even in the public service, proves as wasteful as 
unregulated competition in private business,’ and Con- 
gress appealed to the National Academy of Sciences for a 
plan for Government surveys to ‘‘secure the best results 
at the least possible cost.’?’ Under instructions by Con- 
egress the National Academy considered all the work 
relating to scientific surveys and reported to Congress 
a plan prepared by a special committee, whose member- 
ship included the illustrious names of Marsh, Dana, 
Rogers, Newberry, Trowbridge, Newcomb, and Agassiz. 
This report, which was adopted by the Academy with 
oniy one dissenting vote, grouped all surveys—geodetie, 
topographic, land parceling, and economic—under two 
distinct heads, surveys of mensuration and surveys of 


8 The views of the writer on ‘‘natural monopolies’’ in the Government 
service are set forth in an address delivered at the centennial celebration 
of the U. S. Coast and Geodetic Survey, April 5, 1916. (See Science, vol. 
43, pp. 659-665, May 12, 1916.) 


184 G. O. Snuth—Government Geological Surveys. 


geology. At that time five independent organizations in 
three different departments were carrying on surveys of 
mensuration, and the Academy recommended that all 
such work be combined under the Coast and Geodetic 
Survey with the new name Coast and Interior Survey. 
For the investigation of the natural resources of the pub- 
he domain and the classification of the public lands a 
new organization was proposed, the United States Geo- 
logical Survey. The functions of these two surveys and 
of a third coordinate bureau in the Interior Department, 
the Land Office, were carefully defined and their inter- 
relations fully recognized and provided for in the plan 
presented to Congress. Viewed in the light of 39 years 
of experience the National Academy plan would be 
indorsed by most of us as eminently practical, and the 
report stands as a splendid example of public service ret:- 
dered by America’s leading scientists. The legislation 
which embodied the entire plan, however, failed of pas- 
sage in Congress. 

The natural activity behind the scenes of the conflicting 
interests represented by those connected with the sev- 
eral surveys may be seen in the legislative history of the 
moves leading up to the creation of the United States 
Geological Survey. In the last session of the 45th Con- 
gress the special legislation embodying the recommenda- 
tions of the National Academy was included in the 
Legislative, Executive, and Judicial Appropriation biil 
as it passed the House of Representatives, while the Sun- 
dry Civil Appropriation bill carried an item simply mak- 
ing effective the longer section in the other appropriation 
bill. The item in the Legislative appropriation bili 
created the office of the Director of the Geological Sur- 
vey, provided his salary, and defined his duties, as well 
as specifically terminating the operations of the three 
older organizations. The item in the Sundry Civil bill as 
it passed the House appropriated $100,000 for the new 
Geological Survey, but when this appropriation bill was 
reported to the Senate a committee amendment added 
the words ‘‘of the Territories,’’ and further amendments 
offered on the floor changed the item so as to provide 
specifically and exclusively for the continuation of the 
Hayden Survey. Other amendments provided small 
appropriations for the completion of the reports of the 
Powell and Wheeler surveys, and the bill passed the Sen- 


G. O. Snuth—Government Geological Surveys. 185 


ate'in this form. The Legislative Appropriation bill was 
similarly pruned, while in the Senate, of all reference to 
the proposed new organization. ‘This bill, however, died 
in conference, but in the last hours of the session the 
conferees on the Sundry Civil bill took unto themselves 
legislative powers and transferred from the dead bill to 
the pending measure all the language which constitutes 
the ‘‘organic act’’ of the United States Geological Sur- 
vey. This action was denounced in the Senate as ‘‘a 
wide departure from the authority that is possessed by 
a conference committee,’’ and it was further stated in 
debate that the inserted provision which created a new 
office and discontinued the existing surveys was one 
‘‘which neither the Committee of the Senate nor the Sen- 
ate itself ever saw.’’ This assertion was perhaps par- 
hamentarily sound in that the language was new to the 
Sundry Civil bill, yet actually the Senate had only two 
days before stricken the same proposed legislation from 
the pending Legislative Appropriation bill. However; 
the House conferees—Representatives Atkins of T’ennes- 
see, Hewett of New York, and Hale of Maine—had real- 
ized their tactical advantage, and the Senate, after a 
brief debate, voted on March 3 to concur in the report of 
the committee of conference, thus reversing all their 
earlier action, in which the friends of the Hayden and 
Wheeler organizations apparently had commanded more 
votes than the advocates of the National Academy plan. 

Clarence King was appointed first. Director of the 
United States Geological Survey on April 3, 1879, and 
began the work of organization. With his proven genius 
for administration, King promptly resolved the doubt as 
to the meaning of the term ‘‘national domain’’ in the 
language defining the duties of the Director by taking the 
conservative side and limiting the work of the new organ- 
ization to the region west of the 102d meridian. This 
region was divided into four geological divisions, and for 
economy of.time and money field headquarters were 
established for these divisions. The Division of the 
Rocky Mountains was placed under Mr. Emmons as 
eeologist in charge, the Division of the Colorado under 
Captain Dutton, the Division of the Great Basin under 
Mr. Gilbert, and the Division of the Pacific under Arnold 
Hague. The Division of the Colorado was intended as 
merely temporary for the purpose of bringing to comple- 


186 G. O. Siith—Government Geological Surveys. 


tion the scientific work of the Powell Survey. Similarly 
Dr. Hayden was given the opportunity to prepare a sys- 
tematic digest of his scientific results. This organ- 
ization of the work and the selection of seolo- 
gists in charge showed the relation of the new and the 
old, and a glance at the personnel of the new Survey 
indicates the extent to which the geologic investigation 
of the Western country was to continue without interrup- 
tion. Of the twenty-four geologists and topographers 
listed in the first administrative report, four had been 
connected with the Powell Survey, two with the Hayden, 
three with the Wheeler, and five with the King Survey. 

In planning the initial work of the United States 
Geological Survey, the Director speaks of the ‘‘most 
important geological subjects’’ and ‘‘mining industries,’’ 
of ‘‘instructive geological: structure’’ and ‘‘great bullion 
yield’’ in the same sentences, so that the intent was plain 
to make the geologic investigations both theoretical and 
practical. 

It was expected that the field of operations of this 
Federal Survey would be at once extended by Congress 
over the whole United States, but the measure making 
this extension, which would simply carry out the intent 
of the framers of the legislation creating the new bureau. 
passed the House alone, and it was only by subsequent 
~ modification of the wording of appropriation items that 
the United States Geological Survey became national in 
scope as well as in name. ‘The critical question of the 
effective coordination of State and Federal geologic sur- 
veys was met by Director King, who corrected an errone- 
‘ous impression ‘‘industriously circulated’’ by stating 
his policy to be to urge the inauguration and continuance 
of State surveys. This was the initial step in the 
cooperation between State and Federal surveys which 
pecame effective on a large scale in subsequent years. 

Though the Geological Survey has extended its opera- 
tions over the whole United States, its largest activities 
have always been directed toward the exploration and 
development of the newer territory in the public-land 
States. All four of its directors had their field training 
in the West: the name of Major Powell, who succeeded 
King in 1880, is inseparably connected with scientific 


2 Hor ee” on this subject, see Minnesota Geol. Survey, Eighth 
Ann. Rept., 1880, p. 173 


G. O. Snuth—Government Geological Surveys. 187 


- exploration; Charles D. Walcott, who was Director from 
1894 to 1907, the period of the Survey’s greatest expan- 
sion, made the largest contribution to the Paleozoic stra- 
tigraphy and paleontology of the West; and the present 
Director spent seven field seasons in the Northern Cas- 
cades and one in a mining district in Utah. The scope of 
the activities both Kast and West as developed during 
the 39 years since the establishment of the new bureau. 
can be best described, perhaps, in terms of its present 
functions as expressed in the organization of to-day. 

The growth of the Survey is measured in the increase 
of annual appropriation from $106,000 in 1879-80 to the 
amount available for the current year—$1,925,520, not 
including half a million dollars from War Department 
appropriations being spent in the topographic work of 
the Survey. The corresponding increase in personnel 
has been from 39, listed in the first report, to 911 holding 
regular appointments at the present time, divided among 
the different branches as follows: <A scientific force of 
173 in the Geologic Branch, 169 in the Water Resources 
Branch, 71 in the Topographic Branch, and 15 in the 
Land Classification Board, with a clerical force of 168 
divided among the same branches, and the remainder 
the technical and clerical employees of the publication 
and administrative branches. These personnel statistics 
are not expressive of normal conditions, since a large 
number of the topographic engineers are commissioned 
officers and thus are not included on the civilian roll, 
while, on the other hand, the classification of the stock- 
raising homestead lands makes the technical force of the 
Water Resources Branch unusually large this year. 

The primary aim of the Geological Survey is geo- 
logic, whether directed by authority of law toward 
the ‘‘examination of the geological structure, mineral 
resources, and products of the national domain,’’ toward 
the preparation of the authorized ‘‘reports upon gen- 
eral and economic geology and paleontology,’’ of the 
‘‘oeologic map of the United States,’’ or of the ‘‘report 
on the mineral resources of the United States,’’ or 
toward the ‘‘continuation of the investigation of the 
mineral resources of Alaska’’ or ‘‘chemical and physi- 
eal researches relating to the geology of the United 


States.’’ The spirit and the purpose of the Sur-. 


vey’s work in all these fields are not believed to have 


188 G. O. Smth—Government Geological Surveys. 


materially changed from those of the founders of the 
science in America. [rom time to time too much empha- 
sis may have appeared to be laid upon applied geology as 
contrasted with pure science, yet the report of the 
National Academy to Congress in terms placed the stress 
upon economic resources and referred to paleontology as 
‘‘necessarily connected’’ with general and economic 
geology. The practical purpose of geologic research 
under Government auspices must be recognized by the 
administrator, whether he be the paleontologist like Wai- 
cott, the philosopher like Powell, or the mining geologist 
like King. That the task of steering the true course is 
no new problem can be seen from the statement of Owen! 
written 70 years ago, and these words describe conditions 
of Government geological work even to-day: 


Scientific researches, which to some may seem purely specu- 
lative and curious, are essential as preliminaries to these 
practical results. Further than such necessity dictates, they 
have not been pushed, except as subordinate and incidental, 
and chiefly at such periods as, under the ordinary requirements 
of public service, might be regarded as leisure moments; so that 
the contributions to science thus incidentally afforded, and which 
a liberal policy forbade to neglect, may be considered, in a 
measure, a voluntary offering, tendered at little or no additional 
expense to the department. 


The increased attention given to mineral resources has 
been a matter of gradual growth. Mr. King earlv 
organized a Division of Mining Geology with Messrs. 
Pumpelly, Emmons, and Becker as geologists in charge, 
to whom were assigned the collection of mineral statis- 
ties for the Tenth Census. These Survey geologists and 
Director King himself held appointments as special 
agents of the Census Bureau, and on the staff selected for 
this work appear the names of T. B. Brooks, Edward 
Orton, T. C. Chamberlin, Eugene A. Smith, George 
Little, J.. Bo Proctor. R.. D> Irvine, Nea aeler: 
John Hays Hammond, Bailey Willis, and G. H. Eldridge, 
indicating the extent to which the supervision of these 
inquiries was placed in the hands of economic geologists. 
This procedure was reverted to by Director Walcott and 
in the last ten vears has become a well-established policy, 
the statistics of annual production of all the important 
mineral products being under the charge of geologists, as 

-20 Owen, D. D., 30th Cong., 1st sess., Senate Doc. No. 57, p. 7, 1848. 


G. O. Suuth—Government Geological Surveys. 189 


best qualified to comprehend the resouxées of the coun- 
try. Another of these special assistants in 1880 was 
Albert Williams, Jr., who became the first chief of the 
Division of Mineral Resources, in 1882. The study of 
ore deposits, which may be said to have begun with the 
Kine Survey, was inspired by King’s own appreciation 
of the broad geologic relations of the distribution of 
mineral wealth and by the detailed studies of individual 
mining districts by his associates, ‘‘based upon facts 
accurately determined in the light of modern geology.’’ 

Geological surveys have been prosecuted in Alaska 
since 1895, and in the last few years the annual appro- 
priation for the work has been the same as that made for 
the expenses of the whole Survey in the first year of its 
history. The Division of Alaskan Mineral Resources is in 
fact a geological survey in itself, except that it shares in 
the administrative machinery of the larger organization 
and has the advantage of the cooperation of the scientific 
specialists of the Survey as they may be needed to sup- 
plement its own force. All the investigations in this dis- 
tant part of the country represent the Geological Survey 
_atits best, for here the organization’s long experience in 
the Western States can be applied to most effective and 
helpful work on the frontier, where the geologist and 
topographer in their exploration do not always follow 
the prospector but often precede him. Undoubtedly no 
greater factor has contributed to the development of 
Alaskan resources than this pioneer work of the Federal 
Survey, yet the work has also contributed notable addi- 
tions to the sciences of geology and geography. 

The first duty laid upon the Director of the Geologica! 
Survey in the law of 1879 was ‘‘the classification of the 
public lands,’’ and this phrase undoubtedly expressed the 
idea of the committee of the National Academy. The 
same legislation, however, contained provision for the 
further consideration by a commission of the classifica- 
tion and valuation of the public lands, as also recom- 
mended by the National Academy. ‘Thus the decision of 
Director King that the classification intended by Con- 
2ress was scientific and was intended for general informa- 
tion and not to aid the Land Office in the disposition of 
land by sale or otherwise was really based upon the 
deliberate opinion of the Public Lands Commission, of 
which he was a member, that classification would seri- 


190) G.O. Snuth—Government Geological Surveys. 


ously impede rapid settlement of the unoceupied lands. 
Nearly forty years later those who are intrusted with the 
land-classification work of the Geological Survey recog- 
nize this familiar argument, which undoubtedly had much 
more force in that earlier stage of the utilization of the 
Nation’s resources of land.1!. The conception of land 
classification as a business policy on the part of the Gov- 
ernment as a landed proprietor belongs rather to this 
day of more intensive development. At present current 
public-land legislation calls for highest use, and hence 
official investigation of natural values and possibilities 
must precede disposition. This type of mineral and 
hydrographic classification of public lands has been in 
progress in increasing amount since 1906, so that now 
the Geological Survey is the kind of scientific adviser to 
the Secretary of the Interior and Commissioner of the 
General Land Office that may have been contemplated by 
the National Academy of Sciences in 1878. It is plain, 
however, to everyone at all conversant with Western con- 
ditions that the recent land-classification surveys in 
Wyoming, for instance—detailed geologic surveys which 
form the basis for the valuation of public coal lands in 
40-acre units—would have possessed no utility in 1871, 
when the coal-land law was passed but when the demand 
for railroad fuel had just begun. 

The land-classification idea is of course the basis of 
the National forest and irrigation movements. The laws 
of 1888 and 1896, which mark the beginning of active 
endorsement by Congress of these conservation move- 
ments, placed upon the Survey the duties of examining 
reservoir sites and forest reserves respectively. The 
earlier of these laws began the investigation of the water - 
resources of the country, which is still an important phase 
of the Survey’s activity, and led to the creation of an inde- 
pendent organization—the Reclamation Service. It is 
easy to trace the beginnings of Federal reclamation of 
arid lands in the pioneer work of Powell, whose report 
in 1878 on the arid region of the United States was the 
first adequate statement of the problem of largest use of 
these lands in terms broader than those of individual- 
istic endeavor. For years, however, Powell’s appeal for 


1'This essential difference between present-day requirements and the 
needs of earlier generations has been discussed by W. C. Mendenhall, the 
geologist in charge of the Land Classification Board of the. Geological 
Survey: Proceedings 2d Pan-American Sci. Cong., 1915-16, 3, 761. 


G. O. Smith—Government Geological Surveys. 191 


Congressional consideration of this National task was 
like the ‘‘voice of one crying in the wilderness.’’ 

In a somewhat similar way the forestry surveys under 
the Geological Survey helped in the organization of a 
separate bureau—now the Forest Service. The other 
important Federal bureau tracing direct relationship to 
the Survey is the Bureau of Mines, established in 1910, 
- which continued the investigations in mining technology 
specifically provided for by Congress for six years under 
the Geological Survey but in some degree begun in the 
early days of the Survey under Directors King and 
Powell. 

Another equally important organization of a public 
nature, though not a Federal bureau, traces its begin- 
nings to the Geological Survey: the Geophysical Labora- 
tory of the Carnegie Institution, which now exercises so 
potent an influence over geologic investigation, had its 
origin in the official work of the Geological Survey’s 
Division of Chemical and Physical Research, and its per- 
sonnel was at first largely recruited from the Survey. 
The highly original experimental work of this laboratory 
_ has extended far beyond the scope of the Survey’s work— 
at least far beyond the scope possible with the Federal 
funds available—yet most of the results of these inves- 
tigations may eventually come under even a strict 
construction of the language used in the Survey’s appro- 
priation ‘‘for chemical and physical researches relating 
to the geology of the United States.”’ 

The topographic work of the present Survey continues 
with constant refinement of standards and economy of 
methods the work of the earlier organizations. The 
primary purpose of these topographic surveys is to pro- 
vide the bases for geologic maps, yet these topographic 
maps, which cover 40 per cent of the area of the United 
States, are used in every type of civil engineering as well 
as by the public generally. The annual distribution by 
sale of half a million of these maps is an index of their 
value to the people. 

The hot discussion that was waged for years on the 
question of military versus scientific administration of 
topographic surveys is in striking corftrast with the 
present concentration of all the topographic mapping 
under the Geological Survey in those areas where it may 
best serve the needs of the Army. In 1916 Congress 
specifically recognized the possibility of greater codp- 


192) G. O. Smith—Government Geological Surveys. 


eration of this kind, both in the appropriation made to 
the Geological Survey and in a special appropriation 
made to the War Department. For a number of years 
indeed special military information had been contributed 
to the Army by the Survey topographers, but since 
March 26, 1917, every Geological Survey topographer 
has worked exclusively on the program of military sur- 
veys laid down by the General Staff of the Army, and the 
places of some of the 44 Survey topographers now in 
France as engineer officers are filled by 34 other reserve 
engineer officers detailed by order of the Secretary of 
War to the Director of the Geological Survey to assist 
in this military mapping and to receive instruction fitting 
them in turn for topographic service in France. 

The contribution of this civilian service to the military 
operations in the present emergency forms a fitting con- 
clusion to this review of a century of Government sur- 
veys. At present 215 members of the Geological Survey 
are in uniform, 107 as engineer officers, two of whom are 
on the staff of the American Commanding General in 
France. In the war work carried on in the United 
States the Survey’s contribution is by no means limited 
tomilitary mapping: the geologists are also mobilized for 
meeting war needs, assisting in developing new sources 
of the essential war minerals, in speeding up production 
of mineral products, in collecting information for the 
purchasing officers both of our own and of the Allied gov- 
ernments, in cooperating with the constructing quarter- 
masters in the location of gravel and sand for structural 
use and in both general and special examinations of 
underground water supply and of drainage possibilities 
at cantonment sites, and in supplying the Navy Depart- 
ment with similar technical data. A special contribution 
has been the application to aerial surveys of photogram- 
metric methods developed in the Alaskan topographic 
work and the perfection of a camera specially adapted to 
airplane use. The utilization of the Survey’s map 
engraving and printing plant for confidential and urgent 
work for both the Army and Navy has necessitated post- 
ponement of eurrent work for the Geological Survey 
itself. Throughout the organization: the records, the 
methods, and the personnel which represent the product 
of many years of scientific activity are all being utilized; 
thus is the experience of the past translated into special 
service in the present crisis. : 


Lull—Development of Vertebrate Paleontology. 198 


Art. VI.—On the Development of Vertebrate Paleon- 
tology; by RicHarp Swann LULL. 


INTRODUCTION. 


Unlike its sister science of Invertebrate Paleontology, 
which has been approached so largely from the viewpoint 
of stratigraphic geology, that of the vertebrates is essen- 
tially a biologic science, having its inception in the mas- 
terly work of Cuvier, who is also to be regarded as the 
founder of comparative anatomy. For long decades, ver- 
tebrate paleontology was simply a branch of comparative 
anatomy or morphology in that it dealt almost exclusively 
with the form and other peculiarities of fossil bones and 
teeth, often in a more or less fragmentary condition, very 
little or no attention being paid to any other system of 
the creature’s anatomy. Distribution both in space and 
in time was recorded, but the value of vertebrates in 
stratigraphy was still to be appreciated and has hardly 
yet come into its own. It is readily seen, therefore, that 
the two departments of paleontology did not enlist the 
_ same workers or even the same type of investigators, for 
while the two sciences have much in common and should 
have more, the vertebratist must, above all else, be a 
morphologist, with a keen appreciation of form and a 
mind capable of retaining endless structural details and 
of visualizing as a whole what may be known only in 
part. The initial work of the brilliant Cuvier set so high 
a standard of preparedness and mental equipment 
that as a consequence, the number of those engaged in 
vertebrate research has never been large as compared 
with the workers in some other branches of science, but 
the results achieved by the few who have consecrated 
their research to the fossil vertebrates has been in the 
main of a high order. 

At first, as has been emphasized, this work was largely 
morphological, dealing both with the individual skeletal 
elements and later with the bony framework as a whole. 
Then came the endeavor to clothe the bones with sinews 
and with flesh—to imagine, in other words, the life- 
appearance of the ages-departed form—with such of its 
habits as could be deduced from structure of body, tooth, 
and limb. Next came the working out of systematic 
series of vertebrates and their marshalling into species, 


Am. Jour. Sci.—FourtH Series, Vou. XLVI, No. 271.—Juty, 1918. 
7 


194 Lull—Development of Vertebrate Paleontology. 


genera, and larger groups, and much time was thus spent, 
especially when rapid discovery brought a continual 
stream of new forms before the systematist, and hence 
some appreciation of the countless hosts of bygone crea- 
tures which peopled the world in the geologic past. This 
systematic work, however, was based upon the most 
painstaking morphologic comparisons and so the science 
was still within the scope of comparative anatomy. 

‘In connection with taxonomic research came increas- 
ingly tangible evidence in favor of the law of evolution; 
investigators turned to the working out of phyletic series 
showing the actual record of the successive evolutionary 
changes that the various races had undergone. Coupled 
with this evolutionary evidence came an increased atten- 
tion to the sequential occurrence in successive geologic 
strata, and the stratigraphic distribution of vertebrates 
became known with greater and greater detail. Then 
followed the assemblage of faunas, which brought the 
study of the fossil forms within the realm of historical 
geology, rather than being the mere phylogeny of a single 
race, and the value of vertebrate fossils as horizon 
markers became more and more appreciated by the stra- 
tigrapher. They serve to supplement the knowledge 
gained from the invertebrates, and in this connection are 
especially valuable in that they often give data concern- 
ing continental formations about which invertebrate 
paleontology is largely silent. 


RISE OF VERTEBRATE PALEONTOLOGY IN EUROPE. 


To those who had been nurtured in the belief in a rela- 
tively recent creation covering in its entirety a period of 
but six days, and occurring but four millenniums before 
the time of Christ, the appearance of the remains of 
creatures in the rocks, the like of which no man ever saw 
alive, must have given scope to the wildest imaginings 
concerning their origin and significance; for many 
believed that not only had no new forms been added to 
the world’s fauna since the creation, except possibly by 
hybridizing, but that none had become extinct save a very 
few through the agency of human interference. The 
supposition was, therefore, that such creatures as were 
thus discovered were still extant in some more remote 
fastnesses of the world. Thus, our second president, 
Thomas Jefferson, who wrote one of the first papers on 


Lull—Development of Vertebrate Paleontology. 195 


American fossil vertebrates, published in 1798, discussed 
therein the remains of a huge ground-sloth which has 
since borne the name Megalonyx jeffersom. Jefferson, 
however, described the great claws as pertaining to a 
huge leonine animal which he firmly believed was yet 
living among the mountains of Virginia. 

Cuvier (1769-1832) has been spoken of as the founder 
of our science. His opportunity lay in the profusion of 
bones buried in the gypsum deposits of Montmartre 
within the environs of the city of Paris. Cuvier’s 
studies of these remains, done in the hght of his very 
broad anatomical knowledge, enabled him to prepare the 
first reconstructions of fossil vertebrates ever attempted 
and to bring before the eyes of his contemporaries a 
world peopled with forms which were utterly extinct. 
That these creatures were no longer lhving, none was a 
better judge than Cuvier, for his prominence was such 
that material was sent him from all parts of the world, to 
which must be added that which he saw in his visits to 
the various museums of HKurope. He felt it safe, there- 
fore, to affirm the unlikelihood of any further discovery 
_ of unknown forms among the great mammals of the pres- 
ent fauna of our globe, and few indeed have been the 
additions since his day. ‘T’o Cuvier is due not alone the 
masterly contribution to the sister sciences of compara- 
tive anatomy and vertebrate paleontology—the Osse- 
ments Fossiles (1812)—but he also announced the 
presence in continental strata of a series of faunas which 
showed a gradual organic improvement from the earliest 
such assemblage to the most modern, an idea of the most 
fundamental importance and one with which he is rarely 
eredited. He believed in the sudden and complete 
extinction of faunas, and the facts then known were in 
accord with this idea, as no common genera nor transi- 
tional forms connected the creatures of the Paris gypsum 
with the mastodons, elephants, and hippopotami which 
the later strata disclosed. It is not remarkable, there- 
fore, that Cuvier advanced his theory of catastrophism to 
account for these extinctions. He should not, however, 
according to Depéret, be credited with the idea of suc- 
cessive re-creations, such as that held by D’Orbigny and 
others, but of repopulation by immigration from some 
area which the catastrophe, be it flood or other destruc- 
tive agency, failed to reach. 


196 Lull—Development of Vertebrate Paleontology. 


Cuvier was followed in Europe by a number of illus- 
trious men, none of whom, however, with the exception of 
Sir Richard Owen, possessed his breadth of knowledge 
of comparative anatomy upon which to base their 
researches among the prehistoric. The more notable of 
them may be enumerated before going on to a discussion 
of the American contributions to the science. 

They were, first, Louis Agassiz, a pupil of Cuvier and 
later a resident of America, whose researches on the fos- 
sil fishes of Europe are a monumental work, the result of 
ten years of investigation in all of the larger museums of 
that continent, and which appeared in 1833-43, while he 
was yet a young man. ‘The fishes were practically the 
only fossil vertebrates to come within the scope of his 
investigations, for his later time was consumed in the 
study of olaciers and of recent marine zoology. Another 
student of these most primitive vertebrates who left 
an enduring monument was Johannes Muller. Huxley, 
Traquair, and Jaekel also did masterly work upon this: 
group, while Smith Woodward of the British Museum is 
considered the highest living authority upon fossil fishes. 

Of the Amphibia, the most famous foreign students 
were Brongniart, Jaeger, Burmeister, Von Meyer, and 
Owen, although Owen’s claim to eminence lies rather in 
the investigations of fossil reptiles which he began in 
1839 and continued over a period of fifty years of 
remarkable achievement. Not only did he describe the 
dinosaurs of Great Britain in a series of splendidly illus- 
trated monographs, but extended his researches to the 
curious reptilian forms from the Karroo formation of 
South Africa. It was to him, moreover, that the estab- 
lishment of the true position of the famous Archeopteryx 
as the earliest known bird and not a reptile is due. Von 
Meyer also enriched the literature of fossil reptiles, 
discussing exhaustively those occurring in Germany, 
while Huxley’s classic work on the crocodiles as well as 
on dinosaurs, and the labors of Buckland, Fraas, Koken, 
Von Huene, Gaudry, Hulke, Seeley, and Lydekker have 
added immensely to our knowledge of the group. 

Of the birds, which at best are rare as fossils, our 
knowledge, especially of the huge flightless moas, is due 
largely again to Owen, and his realization of the syste- 
matic position of Archeopteryx has already he men- 
tioned. 


Lull—Development of Vertebrate Paleontology. 197 


The mammals were, perhaps, the most prolific source 
of paleontological research during the nineteenth cen- 
tury, for, as Zittel has said, Cuvier’s famous investiga- 
tions on the fossil bones, mentioned above, not only 
contain the principles of comparative osteology, but also 
show in a manner which has never been surpassed how 
fossil vertebrates ought to be studied, and what are the 
broad inductions which may be drawn from a series of 
methodical observations. Such was Cuvier’s influence 
that until Darwin began to interest himself in mammalian 
paleontology the study of these forms was conducted 
entirely along the lines indicated by the French savant. 
This was seen in a large work, Osteology of Recent and 
Fossil Mammalia, by De Blainville, which, although not 
up to the standard set by the master, is nevertheless a 
notable contribution, as was also the Osteology prepared 
by Pander and D’Alton. A summary of the knowledge of 
the fossil Mammalia up to the year 1847 is contained in 
Giebel’s Fauna der Vorwelt, and Lydekker has done for 
the mammals in the British Museum what Smith Wood- 
ward did for the fishes, producing vastly more than the 
mere catalogue which the title implies. 

The first work wherein the fossil mammals were 
treated genealogically was Gaudry’s Enchainements du 
Monde Animal, written in 1878. Other work on the 
fossil Mammalia was done by Kaup, who described those 
from the Mainz basin and from Epplesheim near Worms 
whence came one of the most famous of prehistoric 
horses, the Hipparion; this horse, together with the 
remarkable proboscidean Dinotherium, was described by 
Von Meyer. One of the most remarkable discoveries, 
ranking in importance, perhaps, next to Montmartre, was 
that of the Pliocene fauna of Pikermi near Athens, 
Greece, first made known through the publications of A. 
Wagener of Munich and later, and much more extensively, 
through that of Gaudry (1862-1867). H. von Meyer was 
Germany’s best authority on fossil Mammalia. After 
his death the work was carried on by Quenstedt, Oscar 
Fraas, Schlosser, Koken, and Pohlig, among others. 

In France, rich deposits of fossil mammals were dis- 
covered in the Department of Puy-de-Diéme, the Rhone 
basin, Sansan, Quercy, and near Rheims. These were 
described by a number of writers, notably Croizet and 
Jobert, Pomel, Lartet, Filhol, and Lemoine. 


198 Lull—Development of Vertebrate Paleontology. 


Riitimeyer of Bale was one of the most famous Huro- 
pean writers on mammalian paleontology, and his 
researches were both comprehensive and clothed in such 
form as to give them a high place in paleontological lit- 
erature. He studied comparatively the teeth of ungu- 
lates, discussed the genealogy of mammals, and the 
relationships of those of the Old and New Worlds. He 
was. an exponent of the law of evolution as set forth by 
Darwin, and his ‘‘genealogical trees of the Mammalia 
show a complete knowledge of all the data concerning the 
different members in the succession, and are amongst the 
finest results hitherto obtained by means of strict scien- 
tific methods of investigation’’ (Zittel, History of Geol- 
ogy and Paleontology, 1901). The mammals of the 
Swiss Eocene have been studied in much detail by 
Stehlin. 

For Great Britain, the most notable contributors were 
Buckland in his Reliquie Diluviane; Falconer, co-author 
with Cautley on the Tertiary mammals of India; Charles 
Murchison, who wrote on rhinoceroses and probosci- 
deans; and more recently Bush, Flower, Lydekker, Boyd 
Dawkins, L. Adams, and C. W. Andrews. . But by far the 
most commanding figure of all was Sir Richard Owen, 
who for half a century stood without a peer as the 
ereatest of authorities on fossil mammals. It was the 
Natural History of the British Fossil Mammals and 
- Birds, published in 1846, that established Sir Richard’s 
reputation. 

Russia has produced much mammalian material, 
especially from the Tertiary of Odessa and Bessarabia, 
and from the Quaternary of northern Russia and Siberia. 
These have been described mainly by J. F. Brandt, A. 
von Nordmann, but especially by Mme. M. Pavlow of 
Moscow. 

Forsyth-Major discovered in 1887 a fauna contem- 
poraneous with that of Pikermi in the Island of Samos 
in the Mediterranean. 

One of the most remarkable recent discoveries of fossil 
localities was that announced in 1901 by Mr. Hugh J. L. 
Beadnell of the Geological Survey of Egypt and Doctor 
C. W. Andrews of the British Museum of London, of 
numerous land and sea mammals of Upper Eocene and 
Lower Oligocene age in northern Heypt. The exposures 
lay about 80 miles southwest of Cairo in the Fayfim dis- 


Lull—Development of Vertebrate Paleontology. 199 


trict and are the sediments of an ancient Tertiary lake, a 
relic of which, Birket-el-Qurun, yet remains. These beds 
contained ancient Hyracoidea, Sirenia, and Zeuglodontia, 
but above all, ancestral Proboscidea which, together with 
those known elsewhere, enabled Andrews to demonstrate 
the origin and evolutionary features of this most remark- 
able group of beasts. This discovery in the Faytim lends 
color to the belief that Africa may have been the ancestral 
home of at least five of the mammalian orders, those men- 
tioned above, together with the Embrithopoda, a group 
unknown elsewhere. This theory had been advanced 
independently by Tullberg, Stehlin, and Osborn, before 
the discovery in Egypt. 

Another European worker of pre-eminence who wrote 
more broadly than the faunal studies mentioned above 
was W. Kowalewsky. He discussed especially the evo- 
lutionary changes of feet and teeth in ungulates, a line of 
research afterward developed in greater detail by the 
Americans, Cope and Osborn. 

South America has yielded series of rich faunas which 
have been exploited by the great Argentinian, Florentino 
Ameghino, and by the Europeans, Owen, Gervais, Hux- 
ley, Von Meyer, and more recently by Burmeister and 
Liydekker. Later exploration and research by Hatcher 
and Scott of North America will be discussed further on 
in this paper. 


VERTEBRATE PALEONTOLOGY IN AMERICA. 


Early Writers——Having thus summarized paleontolog- 
ical progress in the Old World, we can turn to a consid- 
eration of the work done in the New, especially in the 
United States, because while the Old World investigation 
has been invaluable, a science of vertebrate paleontology, 
very complete both as to its zoological and geological 
scope and in the extent and value of published results, 
could be built exclusively upon the discoveries and 
researches made by Americans. The science of verte- 
brate paleontology may be said to have had its beginnings 
in North America with the activities of Thomas Jeffer- 
son, who, like Franklin, felt so strong an interest in 
scientific pursuits that even the graver duties of the high- 
est office in the gift of the American people could not 
deter him from them. When in 1797 Jefferson came to 


260 Lull—Development of Vertebrate Paleontology. 


be inaugurated as vice-president of the United States, he 
brought with him to Philadelphia not only his manuseript 
but the actual fossil bones upon which it was based. 
Again in 1801 he was greatly interested in the Shawan- 
gunk mastodon, despite heavy cares of state, and in 1808 
made part of the executive mansion in Washington serve 
as a paleontological laboratory, displaying therein for 
study the bones of proboscideans and their contempora- 
ries which the Big Bone Lick of Kentucky had produced. 
Jefferson’s work would not, perhaps, have been epoch- 
making were it not for its unique chronological position 
in the annals of the science. 

Jefferson was followed by another man—this time one 
whose diverging lines of interest led him not into the 
realm of political service, but of art, for Rembrandt 
Peale possessed an enviable reputation among the early 
painters of America. Peale published in 1802 an account 
of the skeleton of the ‘‘mammoth,’’ really the mastodon, 
M. americanus, speaking of it as a nondescript carnivor- 
ous animal of immense size found in America. It was 
because of the form of the molar teeth that Peale said of 
it: ‘‘If this animal was indeed carnivorous, which I 
believe cannot be doubted, though we may as philoso- 
phers regret it, as men we cannot but thank Heaven that 
its whole generation is probably extinct.’’ 

With the work of these men as a beginning, it is not 
strange that the more conspicuous Pleistocene fossils of 
the East should have attracted the attention of many 
subsequent writers in the first part of the nineteenth cen- 
tury, nor that the early papers to appear in the Journal 
should pertain to proboscideans or to the huge edentate 
eround-sloths and the aberrant zeuglodons whose bones 
frequently came to light. Therefore a number of men 
such as Koch, both Sillimans, J. C. Warren, and others 
made these forms their chief concern. 

Fossil Footprints——Among the early writers who con- 
cerned themselves with these greater fossils was Edward 
Hitchcock, sometime president of Amherst College, and 
a geologist of high repute among his contemporaries. 
Hitchcock is, however, better and more widely known as 
the pioneer worker on a series of phenomena displayed 
as in no other place in the region in which he made his 
home. These are fossil footprints impressed upon the 
Triassic rocks of the Connecticut valley. It was in the 


Lull—Development of Vertebrate Paleontology. 201 


Journal for the year 1836 (29, 307-340) that Hitchcock 
first called attention to the footmarks, although they had 
been known and discussed popularly for a number of 
years previous. James Deane, of Greenfield, was per- 
haps the first to appreciate the scientific interest of these 
phenomena, but deeming his own qualifications insuff- 
cient properly to describe them, he brought them to the 
attention of Hitchcock, and the interest of the latter 
never waned until his death in 1864. Hitchcock wrote 
paper after paper, publishing many of them in the Jour- 
nal, again in his Final Report on the Geology of Massa- 
chusetts (1841), and later in quarto works, one in the 
Memoirs of the American Academy of Arts and Sciences 
and the two others under the authority of the Common- 
wealth, the Ichnology in 1858, and the Supplement in 
1865, the last being a posthumous work edited by his son, 
Charles H. Hitchcock. 

Hitcheock’s conception of the track-makers was more 
or less imperfect because of the fact that for a long time 
but a few fragmentary osseous remains were known, 
either directly or indirectly associated with the tracks, 
while on the other hand the bird-like character of many 
of the latter and the discovery of huge flightless birds 
elsewhere on the globe suggested a very close analogy if 
not a direct relationship. Hence ‘‘bird tracks’’ they 
were straightway called, a designation which it has been 
difficult to remove, even though in 1843 Owen called atten- 
tion to the need of caution in assuming the existence of 
so highly organized birds at so early a period, especially 
when large reptiles were known which might readily 
form very similar tracks. The footprints are now 
believed to be very largely of dinosaurian origin, and 
dinosaurs whose feet corresponded in every detail with 
the footprints have actually come to light within the same 
geologic and geographic limitations. This of course 
refers to the bipedal, functionally three-toed tracks. Of 
the makers of certain of the obsecurer of the quadrupedal 
trails we are as much in the dark to-day as were the 
first discoverers of a century ago, so far as demonstrable 
proof is concerned. We assume, however, that they were 
the tracks of amphibia and reptiles, beyond which we may 
not go with certainty. 

Agassiz, writing in 1865 (Geological Sketches), says: 


202 Lull—Development of Vertebrate Paleontology. 


‘To sum up my opinion respecting these footmarks, I believe 
that they were made by animals of a prophetic type, belonging 
to the class of reptiles, and exhibiting many synthetic charac- 
ters. The more closely we study past creations, the more 
impressive and significant do the synthetic types, presenting 
features of the higher classes under the guise of the lower ones, 
become. They hold the promise of the future. As the opening 
overture of an opera contains all the musical elements to be 
therein developed, so this living prelude of the creative work 
comprises all the organic elements to be successively developed 
in the course of time.’ 


Of those whose work was contemporaneous with that 
of Hitchcock, but one, W. C. Redfield, wrote on Triassic 
phenomena, and he concerned himself mainly with the 
fossil fishes of that time, his first paper on this subject 
appearing in 1837 in the Journal (34, 201), and the last 
twenty years later. 

Paleozoic Vertebrates——lLater the vertebrates of the 
Paleozoic began to attract attention, footprints from 
Pennsylvania being described by Isaac Lea, beginning in 
1849, a notice of his first paper appearing in the Journal 
for that year (9, 124). Several papers followed on the 
reptile Clepsysaurus. Alfred King also wrote on the 
Carboniferous ichnites, his work slightly antedating that 
of Lea, but being less authoritative. 

But by far the most illuminating of the mid-century 
writers on Paleozoic vertebrates was Sir William Daw- 
son, a very large proportion of whose numerous papers 
relate to the Coal Measures of Nova Scotia and their 
contained plant and animal remains. In 1853 appeared 
Dawson’s first announcement, written in collaboration 
with Sir Charles Lyell, of the finding of the bones of 
vertebrates within the base of an upright fossil tree trunk 
at South Joggins. These bones were identified by Owen 
and Wyman as pertaining to a reptilian or amphibian to 
which the name Dendrerpeton acadianum was given. 
Following this were several papers published in the 
Quarterly Journal of the Geological Society, London, 
describing more vertebrates and associated terrestrial 
molluses. In 1863 Dawson summarized his discoveries 
in the Journal (36, 430-432) under the title of ‘‘Air- 
breathers of the Coal Period,’?’ a paper which was 
expanded and published under the same title in the Cana- 
dian Naturalist and Geologist for the same year. Daw- 
son also printed in the same volume the first account of 


Lull—Development of Vertebrate Paleontology. 203 


-reptilian(?) footprints from the coal. Thus from time 
to time there emanated from his prolific pen the account 
of further discoveries, both in bones and footprints, his 
final synopsis of the air-breathing animals of the Paleo- 
zoic of Canada appearing in 1895. The only other group 
of vertebrates which claimed his attention were certain 
whales, on which he occasionally wrote. 

Fishes.—The fossil fishes from the Devonian of Ohio 
found their first exponent in J. S. Newberry, appointed 
chief geologist of the second geological survey of Ohio, 
which was established in 1869. These fishes from the 
Devonian shales belonged for the greater part to the 
curious group of armored placoderms, the remains of 
which consist very largely of armor plates with little or 
no traces of internal skeleton. There was also found in 
association a shark, Cladoselache, of such marvelous 
preservation that from some of the Newberry specimens 
now in the American Museum of Natural History, New 
York, Bashford Dean has demonstrated the histology of 
muscle and visceral organs, in addition to the very com- 
plete skeletal remains. 

Newberry’s work on these forms, begun in 1868, has 
been carried to further completion by Bashford Dean and 
his pupil L. Hussakof, as well as by C. R. Eastman. 
Newberry’s other paleontological work was with the Car- 
boniferous fishes of Ohio, the Carboniferous and Triassic 
fishes of the region from Sante Fé to the Grand and 
Green rivers, Colorado, and on the fishes and plants of 
the Newark system of the Connecticut valley and New 
Jersey. He also discussed certain mastodon and mam- 
moth remains, and those of the peccary of Ohio, 
Dicotyles. 


Jos—EPH Leripy (1823-1891). 


We now come to a consideration of the work of Joseph 
Leidy, one of the three great pioneers in American verte- 
brate paleontology, for if we disregard the work of Hitch- 
cock and others on the fossil footprints, few of the results 
thus far obtained were based upon the fruits of organized 
research. Leidy began his publication in 1847 and con- 
tinued to issue papers and books from time to time until 
the year 1892, having published no fewer than 219 paleon- 
tological titles, and 553 all told. His earlier paleontolog- 
ical researches were exclusively on the Mammalia, which 


204 Lull—Development of Vertebrate Paleontology. 


were then coming in from the newly discovered fossil 
localities of the West. The discovery of these forms, 
one of the most notable events in the history of our 
science, will bear re-telling. 
| The first announcement was made in 1847, when Hiram 
A. Prout of St. Louis published in the J ournal (3, 248- 
250) the description of the maxillary bone of ‘‘Paleéo- 
thervum’’ (=Titanotherwm prouti) from near White 
River, Nebraska. This at once drew the attention of 
geologists and paleontologists to the Bad Lands, or 
Mauvaises Terres, which were to prove so highly produc- 
tive of fossil forms. About the same time S. D. Culbert- 
son of Chambersburg, Pennsylvania, submitted to the 
Academy of Natural Sciences at Philadelphia some fos- 
sils sent to him from Nebraska by Alexander Culbertson. 
These were afterward described by Leidy in the Pro- 
ceedings of the Academy, together with the paleotheroid 
jaw, in addition to which three other collections which 
had been made were also placed at his disposal for study. 
This aroused the interest of Doctor Spencer F. Baird 
of the Smithsonian Institution, who sent T. A. Culbert- 
son to the Bad Lands to make further collections. The 
latter was successful in securing a valuable series of 
mammalian and chelonian remains. These, together 
with other specimens from the same locality, were sent 
to Leidy, for, as Baird remarked, Leidy, although only 
thirty years of age, was the only anatomist in the United 
States qualified to determine their nature. The outcome 
of Leidy’s study of this material was -‘‘The Ancient 
Fauna of Nebraska,’’ published in 1853, and constituting 
the most brilliant work which up to that time American 
paleontology had produced. Leidy’s determinations, 
which are in the main correct, are the more remarkable 
when it is realized that he had little recent osteolog- 
ical material for comparative study. The forms thus 
described by him were new to science, of a more gener- 
alized character than those now living, and yet their 
distinguished describer recognized, either at that time or 
a little later, their true relationship to the modern types. 
The extent of Leidy’s anatomical knowledge was almost 
Cuvierian, and Cuvier-like he established the fact of the 
presence of the rhinoceroses, then unheard of in the 
American fauna, from a few small fragments of molar 
teeth, an opinion shortly to be fully sustained through the 


Lull—Development of Vertebrate Paleontology. 205 


finding of complete molars and the entire skull of the 
same individual animal. 

Leidy next turned his attention to the huge edentates, 
which he studied exhaustively, publishing his results in 
the form of a memoir in 1855, two years after the appear- 
ance of the ‘‘Ancient Fauna.’’ 

Extinct fishes of the Devonian of Illinois and Missouri 
and the Devonian and Carboniferous of Pennsylvania 
were made the subjects of his next researches, after 
which he described the peccaries of Ohio, and later, in a 
much larger and most important work, the Cretaceous 
reptiles of the United States (1865). Most of the fossils 
discussed in this last work are from the New Jersey Cre- 
taceous marls and of them the most notable was the 
herbivorous dinosaur Hadrosaurus, the structure and 
habits of which, together with its affmities with the Old 
World iguanodons, Leidy described in detail. From 
Leidy’s descriptions and with his aid, Waterhouse Haw- 
kins was enabled to restore a replica of the skeleton in a 
remarkably efficient way. This restoration for a long 
time graced the museum of the Philadelphia Academy of 
Natural Sciences and there was a plaster replica of it in 
the United States National Museum. These, together 
with plaster replicas of Igwanodon from the Royal Col- 
lege of Surgeons in London, gave to Americans their first 
real conceptions of members of this most remarkable 
eroup. The associated fossils from the New Jersey 
marls were chiefly crocodiles and turtles. 

From 1853 to 1866 F. V. Hayden was carrying on a 
series of most energetic explorations in the West, 
especially in Nebraska and Dakota as then delimited, 
returning from each trip laden with fossils which were 
given to Leidy for determination. The results appeared 
in 1869 in Leidy’s Extinct Mammalian Fauna of Dakota 
and Nebraska, published as volume 7 of the Journal of 
the Philadelphia Academy. In this large volume no fewer 
than seventy genera and numerous species of forms, 
many of them new to science, were described, repre- 
senting many of the principal mammalian orders; horses 
were, however, especially conspicuous. This last group 
led Leidy to the conclusion, afterward emphasized by 
Huxley, that North America was the home of the horse in 
geologic time, there being here a greater representation 
of different species than in any recent fauna of the 


206 Lull—Development of Vertebrate Paleontology. 


world. lLeidy’s interest in the horses, for the forward- 
ing of which he made a large collection of recent mate- 
rial, extended over many years, as his first paper on the 
subject bears the date of 1847, the last that of 1890. 

Next came the discovery of Eocene material from the 
vicinity of Fort Bridger, Wyoming, geologically older 
than the Nebraska and Dakota formations. This, 
together with specimens from the Green River and 
Sweetwater River deposits of Wyoming and the John 
Day River. (Oligocene) of Oregon, was also referred to 
Leidy, and added yet more to the list of newly discov- 
ered species with which he had already become familiar 
in Ins earlier researches. The results of this study were 
published by the Hayden Survey in 1873, under the title 
bei oniuibniioms to the Extinct Vertebrate Fauna of the 
Western Territories.’’ This was the last of Leidy’s 
major works, but he continued up to the time of his death 
to report to the Academy concerning the various fossil 
forms that were submitted to him for identification. Of 
such reports the most important was one on the fossils 
of the phosphate beds of South Carolina, published in 
the Journal of the Academy in 1887. 

As a paleontologist, Leidy ranks with Cope and 
Marsh high among those who enriched the American Iit- 
erature of the subject, but it must be remembered that 
this was but a single aspect of his many-sided scientific 
career, for he made many contributions of high order to 
botany, zoology, and general and comparative anatomy 
as well, nor did his knowledge and usefulness as an 
instructor of his fellow men keep within the limitations of 
these subjects. 


OTHNIEL CHARLES Marsu (1831-1899). 


The sixth decade of the nineteenth century saw the 
beginning of the labors of several paleontologists who, 
like Leidy, were destined to raise the science of fossil 
vertebrates in America to the level of attainment of the 
Old World. They were, among others, Othniel Charles 
Marsh and Edward Drinker Cope. Of these the names 
of Marsh and Cope are linked together by the brilliance 
of their attainments, their contemporaneity, and the 
rivalry which the similarity ef their pursuits unfortu- 
nately engendered. Marsh produced his first paleon- 


Lull—Development of Vertebrate Paleontology. 207 


tological paper in 1862 (33, 278), Cope in 1864, but the 
latter died first, so that his life of research was shorter. 

To Professor Marsh should be given credit for the 
first organized expedition designed exclusively for the 
collection of vertebrate remains, the results of which con- 
tain so much material that it has not yet entirely seen 
the light of scientific exposition. Marsh’s first trip to 
the West was in 1868, the first formal expedition being 
organized two years later. These expeditions, of which 
there were four, were privately financed except for the 
material and military escort furnished by the United 
States Government, and consisted of a personnel drawn 
entirely from the graduate or undergraduate body 
of Yale University. These parties explored Kansas, 
Nebraska, Wyoming, Utah, and Oregon, and returned 
laden with material from the Cretaceous and Tertiary 
formations of the West. Some of this is of necessity 
somewhat fragmentary, but type after type was secured 
which, with his exhaustive knowledge of comparative 
anatomy, enabled Marsh to announce discovery after dis- 
covery of species, genera, families, and even orders of 
mammals, birds, and reptiles which were unknown to 
science. The year 1873 saw the last of the student expe- 
ditions, and thereafter until the close of his life the work 
of collecting was done under Marsh’s supervision, but by 
paid explorers, many of whom had been his scouts and 
euides in the formal expeditions or had been especially 
trained by him in the Hast. In 1882, after fourteen years 
of the experience thus gained, Marsh was appointed verte- 
brate paleontologist to the United States Geological Sur- 
vey, which relieved him in part of the personal expense 
connected with the collecting, although up to within 
a short time of his death his own fortune was very 
largely spent in enlarging his collections. After his con- 
nection with the Survey was established, Marsh had two 
main purposes in view in making the collections: (1) to 
determine the geological horizon of each locality where 
a large series of vertebrate fossils was found, and (2) to 
secure from these localities large collections of the more 
important forms sufficiently extensive to reveal, if possi- 
ble, the life histories of each. Marsh believed that the 
material thus secured would serve as key or diagnostic 
fossils to all horizons of our western geology above the 
Paleozoic, a belief in which he was in advance of his time, 


208 Lull—Development of Vertebrate Paleontology. 


for few of his contemporaries appreciated the value of 
vertebrates as horizon markers. The result of the ful- 
filment of his second purpose saw the accumulation of 
huge collections from all horizons above the Triassic and 
some Paleozoic and Triassic as well. These contained 
some very remarkable series, each of which Marsh hoped 
to make the basis of an elaborate monograph to be pub- 
lished under the auspices of the Survey. One ean vis- 
ualize the scope of his ambitions by the fact that no fewer 
than twenty-seven projected quarto volumes, to contain 
at least 850 lithographic plates, were listed by him in 
1877. ‘These covered, among other groups, the toothed 
birds (Odontornithes), Dinocerata, horses, brontotheres, 
pterodactyls, mosasaurs and plesiosaurs, monkeys, car- 
nivores, perissodactyls and artiodactyls, crocodiles, 
lizards, dinosaurs, various birds, proboscideans, eden- 
tates and marsupials, brain evolution, and the Connecti- 
cut Valley footprints. Much was done towards the prep- 
aration of these memoirs, as evidenced by the long list 
of preliminary papers, admirably illustrated by woodcuts 
which were to form the text figures of the memoirs, 
which appeared with great regularity in the pages of the 
Journal for a period of thirty years. Of the actual 
memoirs, however, but two had been published at the 
time of Marsh’s death in 1899—the Odontornithes in 
1880 and the Dinocerata in 1884. One must not overlook, 
however, the epoch-making Dinosaurs of North Ameriea, 
which was published by the Survey in 1896, although it 
was not in the form nor had it the scope of the proposed 
monographs. This was not due to lack of application, 
for Professor Marsh was an indefatigable worker, but 
rather to the fact that the program was of such magni- 
tude as to necessitate a patriarchal life span for its con- 
- summation. As it is, Professor Marsh’s fame rests first 

upon his ability and intrepidity as a collector, ready him- 
self to brave the very certain hardships and dangers 
which beset the field paleontologist in the pioneer days, 
and also by his judgment and command of men to secure 
the very adequate services of others and so to direct . 
their endeavors that the results were of the highest value. 
The material witness to Marsh’s skill as a collector lies 
in the collections of the Peabody Museum at Yale and in 
the Marsh collection at the United States National 
Museum, the latter secured through the funds of. the 
United States Geological Survey. Together they consti-_ 


Lull—Development of Vertebrate Paleontology. 2099 


tute what is possibly the greatest collettion of fossil 
vertebrates in America, if not in the world; individually, 
they are second only to that of the American Museum in 
New York City, the result of the combined labors of 
Osborn and Cope and their very able corps of assistants. 

As a scientist Marsh possessed in large measure that 
wide knowledge of comparative anatomy so necessary to 
the vertebrate paleontologist, and as a consequence was 
not only able to recognize affinities and classify unerr- 
ingly, but also to recognize the salient diagnostic fea- 
tures of the form before him and in few words so to 
describe them as to render the recognition of the species 
by another worker relatively easy. The publication of 
hundreds of these specific diagnoses in the Journal con- 
stitutes a very large and valuable part of that periodi- 
eal’s contribution to the advancement of our science. 
Marsh’s method of indicating forms by so brief a state- 
ment leaves much to be done, however, in the way of 
further description of his types, which in many instances 
were but partially prepared. 

Yet another important service which Marsh rendered 
to science was the restoration of the creatures as a whole, 
made with the most painstaking care and precision 
through assembling the drawings of the individual bones. 
These restorations have become classic, embracing as they 
did a score or more of forms, of beast, bird, and reptile. 
They also were published first in the Journal, although 
they have subsequently been reproduced in text-books 
and other works the world over. Part of Marsh’s popu- 
lar reputation, at least, which was second to that of no 
other American in his line, was due to his skill in 
attaining publicity, for his papers, of whatever extent, 
were carefully and methodically sent to correspondents 
in the uttermost parts of the earth, and thus the Marsh 
collection has reflected the fame of its maker. 


Epwarp DRINKER Cope (1840-1897). 

The third- great name in American vertebrate paleon- 
tology, that of Edward Drinker Cope, stands out in sharp 
contrast with the other two, although in the range of his 
interests he was probably more nearly comparable with 
Leidy than with Marsh. The beginning of Cope’s scien- 
tific labors dates from 1859, the year made famous in the 
annals of science by the appearance of Darwin’s Origin 
of Species. It is not surprising, therefore, that matters 


210 Lull—Development of Vertebrate Paleontology. 


evolutional should have interested him to the very end of 
his career. Cope was not merely a paleontologist, but was 
interested in recent forms, especially the three lower 
classes of vertebrates, to such an extent that his work 
therewith is highly authoritative and in some respects 
epoch-making. Thirty-eight years of almost continual 
toil were his, and the mere mass of his literary productions 
is prodigious, especially when one realizes that, unlike 
those of a writer of fiction, they were based on painstaking 
research and philosophical thought. The greater part of 
_ Cope’s life was spent in or near Philadelphia except for 
his western explorations, and he is best known as pro- 
fessor of geology and paleontology in the University of 
Pennsylvania, although he served other institutions as 
well. 

Cope’s early work was among the amphibia and rep- 
tiles, his first paleontological paper, the description of 
Amphibamus grandiceps, appearing in 1865. This year 
he also began his studies of the mammals, especially the 
Cetacea, both living and extinct, from the Atlantic sea- 
board. The next year saw the beginning of his work on 
the material from the Cretaceous marls of New, Jersey, 
describing therefrom one of the first carnivorous dino- 
saurs, Lelaps, to be discovered in America. In 1868_ 
Cope began to describe the vertebrates from the Kansas 
chalk and three years later made his first exploration of 
these beds. This led to his connection with the United 
States Geological Survey of the Territories under Hay- 
den, and to continued exploration of Wyoming and Col- 
orado in 1872 and 1873. The material thus gained, 
consisting of fishes, mosasaurs, dinosaurs, and other 
reptiles, was described in the Transactions of the 
American Philosophical Society as well as in the Survey 
Bulletins. In 1875 these results were summarized .in a 
large quarto volume entitled ‘‘Vertebrata of the Creta- 
ceous formations of the West.’’ Subsequent summers 
were spent in further exploration of the Bridger, Washa- 
kie, and Wasatch formations of Wyoming, the Puerco 
and Torrejon of New Mexico, and the Judith River of. 
Montana. The material gathered in New Mexico proved 
particularly valuable, and led to the publication in 1877 
of another notable volume entitled ‘‘Report upon the 
Extinet Vertebrata obtained in New Mexico by Parties 
of the Expedition of 1874.”’ ae 


Lull—Development of Vertebrate Paleontology. 211 


Material was now accumulating so fast as to necessi- 
tate the concentration of Cope’s own time on research, 
so that, while he continued to make brief journeys to the 
West, the real work of exploration was delegated to 
Charles H. Sternberg and J. L. Wortman, both of whom 
became subsequently very well known, the former as a 
collector whose active service has not yet ceased, the 
latter as an explorer and later an investigator of 
extremely high promise. 

As early as 1865, Cope began no fewer than five sep- 
arate lines of research which he pursued concurrently 
for the remainder of his career. On the fishes, he became 
a high authority in the larger classification, owing to his 
researches into their phylogeny, for which a knowledge 
of extinct forms is imperative. On amphibia, he wrote 
more voluminously than any other naturalist, discussing 
not only the morphology but the paleontology and tax- 
onomy as well. In this connection must be mentioned 
not only Cope’s exploration and collections in the Per- 
mian of Ohio and Illinois, but especially the remains 
from the Texas Permian, first received in 1877, upon 
which some of his most brilliant results were based; 
these of course included reptilian as well as amphibian 
material. His third line of research, the Reptilia, is in 
part included in the foregoing, but also embraced the 
reptiles of the Bridger and other Tertiary deposits, those 
of the Kansas Cretaceous, and the Cretaceous dinosaurs. 

Up to 1868 Leidy alone was engaged in research in the 
West, but that year saw the simultaneous entrance of 
Marsh and Cope into this new field of research, and their 
exploration and descriptions of similar regions and forms 
soon led to.a rivalry which in turn developed into a most 
unfortunate series of controversies, mainly over the sub- 
ject of priority. This resulted in a permanent rupture 
of friendship and the division of American workers into 
two opposing camps to the detriment of the progress of 
our science. This breach has now been happily healed, 
and for a number of years the degree of mutual good will 
and aid on the part of our workers has been of the high- 
est sort. 

The extent of the western fossil area, and particularly 
the explorations of three of Cope’s aids, Wortman in the 
Big Horn and Wasatch basins, Baldwin in the Puerco of 
New Mexico, and Cummins in the Permian of Texas, gave 
him so fruitful a field of endeavor that the occasion for 


212 Lull—Development of Vertebrate Paleontology. 


jealous rivalry was largely removed. The most manifest 
result of Cope’s western work was the publication in 
1883 of his Vertebrata of the Tertiary Formations of the 
West, which formed volume 3 of the quarto publications 
of the Hayden Survey. This huge book contains more 
than 1000 pages and 80 plates and has been facetiously 
called ‘‘Cope’s Bible.’’ 

Cope’s philosophical contributions, which covered the 
domains of evolution, psychology, ethics, and meta- 
_ physics, began in 1868 with his paper on The Origin of 
Genera. In evolution he was a follower of Lamarck, and 
as such, with Hyatt, Ryder, and Packard, was one of the 
founders of the so-called Neo-Lamarckian School in 
America. Cope’s principal contribution, set forth in his 
Factors of Organic Evolution, is the idea of kinetogenesis 
or mechanical genesis, the principle that all structures 
are the direct outcome of the stresses and strains to 
which the organism is subjected. Weismann’s forcible 
attack on the transmission theory did not shake Cope’s 
faith in these doctrines, for he claimed that the paleon- 
tological evidence for the inheritance of such characters 
as are apparently the result of individual modification 
was too strong to be refuted. Cope was more like 
Lamarck than any other naturalist in his mental make-up 
as well as his ideas. He was also, like Haeckel, given 
to working out the phylogeny of whatever type lay before. 
him, and in many instances arrived marvellously near the 
truth as we now see it. 

Associated for a while with A. S. Packard, Cope soon 
became chief editor and proprietor of the American Nat- 
uralist, which was for many years his main means of pub- 
lication and thus served our science in a way comparable 
to the Journal. As Osborn says by way of summation: 


‘“Cope is not to be thought of merely as a specialist in Paleon- 
tology. After Huxley he was the last representative of the old 
broad-gauge school of anatomists and is only to be compared 
with members of that school. His life-work bears marks of great 
genius, of Solid and accurate observation, and at times of inac- 
curacy due to bad logic or haste and overpressure of work. 

. As a comparative anatomist he ranks both in the range 
and effectiveness of his knowledge and his ideas with Cuvier and 
Owen. . . . As a natural philosopher, while far less logical 
than Huxley, he was more creative and constructive, his meta- 
physics ending in theism rather than agnosticism.’’ 


Lull—Development of Vertebrate Paleontology. 212 


1870-1880. 


The seventh decade was productive of comparatively 
few great names in the history of our science, but two, 
J. A. Ryder and Samuel W. Williston, being notable con- 
tributors. The former produced but few papers and 
those between 1877 and 1892, yet they were of note and 
such was their influence that he is named with Hyatt, 
Packard, and Cope as one of the founders of the Neo- 
Lamarckian School of evolutionists in America. Ryder 
was a particular friend and a colleague of Cope, as they 
_were both concerned with the back-boned animals, while 
the other two were invertebratists. Ryder wrote on 
mechanical genesis of tooth forms and on seales of fishes, 
also on the morphology and evolution of the tails of 
fishes, cetaceans, and sirenians, and of the other fins of 
aquatic types. He did, on the other hand, practically no 
systematic or descriptive work. 

Williston, on the contrary, has had a long and varied 
career as an investigator and as an educator. Trained 
at Yale, he prepared for medicine, and much of his teach- 
ing has been of human anatomy, both at Yale and at the 
University of Kansas where he served for a number of 
years as dean of the Medical School. He is also a stu- 
dent of flies, and as such not only the foremost but indeed 
almost the only dipterologist in the United States. But 
it is with his work as a vertebrate paleontologist that we 
are chiefly concerned, and here again he stands among 
the foremost. His initial work and training in this 
department of science were with Marsh, for whom he 
spent many months im field work, collecting largely in the 
Niobrara Cretaceous of Kansas. He did, however, no 
research while with Marsh, owing to the latter’s disin- 
clination to foster such work on the part of his associates. 
Williston began his publications in 1878 and has con- 
tinued them until the present, working mainly with Cre- 
taceous mosasaurs, plesiosaurs, and pterodactyls. Of 
late, since his transference to the University of Chicago, 
where as professor of paleontology and director of the 
Walker Museum he has served since 1902, his interest has 
lain mainly among the Paleozoic reptiles and amphibia. 
Williston’s more notable works are American Permian 
Vertebrates and Water Reptiles of the Past and Present, 
wherein he sets forth his views of the phylogenesis and 
taxonomy of the reptilian class. He is at present at 


214 Lull—Development of Vertebrate Paleontology. 


work on the evolution of the reptiles, a volume which is 
eagerly awaited by his colleagues. It is in morphology 
that Williston’s greatest strength les and some of 
his most effective work on the mosasaurs has appeared 
in the Journal. 


1880-1900. 


The next decade, that of 1880-1890, saw a number of 
notable additions to the workers in vertebrate paleontol- 
ogy: Henry F. Osborn, W. B. Scott, R. W. Shufeldt, J. L. 
Wortman, George Baur, F. A. Lucas, and F. W. True. 
Shufeldt is our highest authority on the osteology of 
birds, both recent and extinct, having recently described 
all of the extinct forms contained in the Marsh collec- 
tion; True wrote of Cetacea; Lucas of marine and Pleis- 
tocene mammals and birds, and has also written popular 
books on prehistoric life. Lucas’s greatest service, how- 
ever, les in the museums, where he has manifested a 
genius second to none in the installation of mute evi- 
dences of living and past organisms. Wortman was for 
a time associated with Cope, later with Osborn in the 
American Museum, again at the Carnegie Museum at 
Pittsburgh, and finally at Yale in research on the Bridger 
Eocene portion of the Marsh collection. His work has 
been chiefly the perfection of field methods in vertebrate 
paleontology, and as a special investigator of Tertiary 
Mammalia, treating the latter largely from the morpho- 
logic and taxonomic standpoints. Wortman’s Yale 
results on the carnivores and primates of the Hocene, 
as yet unfinished, were published in the Journal in > 
1901-1904. | 

William B. Scott is a graduate of Princeton, and has 
spent thirty-four years in her service as Blair Professor 
of Geology and Paleontology. His first publication, in 
1878, issued in conjunction with Osborn and Speir, 
described material collected by them in the Kocene for- 
mations of the West, and since that time Scott’s research 
has been entirely with the mammals, on which he is one of 
our highest authorities. His most notable works have 
been a History of Land Mammals of the Western Hemi- 
sphere, 1913, and the results of the Patagonian expedi- 
tions by Hatcher, which are published in a quarto series 
in conjunction with W. J. Sinclair, although they are the 
authors of separate volumes, Scott’s work being mainly 


Lull—Development of Vertebrate Paleontology. 215 


on the carnivores and edentates of the Santa Cruz forma- 
tion. Itis as a systematist in research and as an educa- 
tor that Scott has attained his highest usefulness. 

The man who, next to the three pioneers, has attained 
the highest reputation in vertebrate paleontologic 
research, is Henry Fairfield Osborn. Graduate of 
Princeton in the same class that produced Scott, Osborn 
served for a time as professor of comparative anatomy 
in that institution, and in 1891 was called to New York to 
organize the department of zoology in Columbia Uni- 
versity and that of vertebrate paleontology in the Ameri- 
ean Museum of Natural History. He had, early in his 
career, gone west in company with Professor Scott, and 
had collected material from the Hocene formation of 
Wyoming, upon which they based their first joint paper 
in 1878, Osborn’s first independent production, a memoir 
on two genera of Dinocerata, appearing in 1881. A num- 
ber of papers followed, on the Mesozoic Mammalia, on 
Cope’s tritubercular theory, and on certain apparent evi- 
dences for the transmission of acquired characters. It 
was, however, with his acceptance of the New York 
responsibilities, especially at the American Museum, 
that Osborn’s most significant work began. Aided first 
by Wortman and Earle, later by W. D. Matthew and 
others, he has built up the greatest and most complete 
- collection of fossil vertebrates extant; its value, how- 
ever, was largely enhanced through the purchase of the 
private collection of Professor Cope, which of course 
ineluded a large number of. types. The American 
Museum collection thus contains not only a vast series 
of representative specimens from every class and order 
of vertebrates, secured by purchase or expedition from 
nearly all the great localities of the world, but an exhi- 
bition series of skulls and partial and entire skeletons 
and restorations which no other institution can hope to 
equal. Based upon this wonderful material is a large 
amount of research, filling many volumes, published for 
the greater part in the bulletin and memoirs of the 
Museum. This research is not only the product of the 
staff, including Walter Granger, Barnum Brown, W. D. 
- Matthew, and W. K. Gregory, but also of a number of 
other American and some foreign paleontologists as well. 

Professor Osborn’s own work has been voluminous, his 
bibliography from 1877 to 1916 containing no fewer than 


216 Lull—Development of Vertebrate Paleontology. 


441 titles, ranging over the fields of paleontology,—which 
of course includes the greater number—geology, correla- 
tion and paleogeography, evolutionary principles exem- 
plified in the Mammalia, man, neurology and embry- 
ology, biographies, and the theory of education. 

In paleontology, Osborn’s researches have been largely 
with the Reptilia and Mammalia, partly morphological, 
but also taxonomic and evolutional. Faunistic studies 
have.also been made of the mammals. Of his published 
volumes the most important are, first, the Age of Mam- 
mals (1910), in which he treats not of evolutionary series 
of phylogenies, but of faunas and their origin, migra- 
tions, and extinctions, and of the correlation of Old and 
New World Tertiary deposits and their contents. Men 
of the Old Stone Age (1916) is an exhaustive treatise and 
is the first full and authoritative American presentation 
of what has been discovered up to the present time 
throughout the world in regard to human prehistory. In 
his latest volume, The Origin and Evolution of Life 
(1917), Osborn presents a new energy conception of evo- 
lution and heredity as against the prevailing matter and 
form conceptions. In this volume there is summed up 
the whole story of the origin and evolution of life on 
earth up to the appearance of man. This last book is 
novel in its conceptions, but it is too early as yet to judge 
of the acceptance of Osborn’s theses by his fellow work- — 
ers in science. : 

Since the death of Professor Marsh, Osborn has served 
as vertebrate paleontologist to the United States Geolog- 
ical Survey, and has in charge the carrying through to 
completion of the many monographs proposed by his dis- 
tinguished predecessor. One of these, that on the horned 
dinosaurs, has been completed by Hatcher and Lull 
(1907), another on the stegosaurian dinosaurs has been 
- carried forward by C. W. Gilmore of the United States 
National Museum, while under Osborn’s own hand are 
the memoirs on the titanotheres (aided by W. K. Greg- 
ory). the horses, and the sauropod dinosaurs. Of these, 
the first, when it shall have been completed, promises to — 
be the most monumental and exhaustive study of a group 
of fossil organisms ever undertaken. 

As a leader in science, a teacher and administrator, 
Professor Osborn’s rank is high among the leading verte- 
bratists. He is remarkably successful in his choice of 


Lull—Development of Vertebrate Paleontology. 217 


assistants and in stimulating them in their productive- 
ness so that their combined results form a very consider- 
able share of the later literature in America. 

The ninth decade ushered in the work of a valuable 
group of students, of whom John Bell Hatcher should be 
mentioned in particular, as his work is done. Graduate 
of Yale in 1884, he spent a number of years assisting 
his teacher, Professor Marsh, mainly in the field, collect- 
ing during that time, either for Yale or for the United 
States Geological Survey, an enormous amount of very 
fine material, especially from the West, although he also 
collected in the older Tertiary and Potomac beds near 
Washington. «In the West he secured no fewer than 
105 titanothere skulls, explored the Tertiary, Judith 
River, and Lance formations, collected and in fact vir- 
tually discovered the remains of the Cretaceous mammals 
and of the horned dinosaurs which he was later privileged 
to deseribe. He then (1893) went to Princeton, which he 
served for seven years, his principal work being explora- 
tions in Patagonia for the EK. and M. Museum, one direct 
result of which was the publication of a large quarto on 
the narrative of the expedition and the geography and 
ethnography of the region. Going to the Carnegie 
Museum in Pittsburgh in 1900, Hatcher carried forward 
the work of exploration and collecting begun for that 
institution by Wortman, and as a partial result prepared 
many papers, the principal ones being memoirs on the 
dinosaurs Haplocanthosaurus and Diplodocus. In 1903, 
with T. W. Stanton of the United States Geological Sur- 
vey, Hatcher explored the Judith River beds and together 
they settled the vexatious problem of their age, the 
published. results appearing in 1905, after Hatcher’s 
death. His last piece of research, begun in 1902 and 
continued until his death in 1904, was an elaborate mono- 
eraph on the Ceratopsia, one of the many projected by 
Marsh. Of this memoir Hatcher had completed some 
150 printed quarto pages, giving a rare insight into the 
anatomy of these strange forms. The final chapters, 
however, which were based very largely upon Hatcher’s 
own opinions, had to be prepared by another hand. 

Despite his early death, therefore, Hatcher rendered 
a very signal service u Agnerican paleontology—in 
exploration, stratigraphy, morphology, and systematic 
revision—and his activity in planning new fields of 
research, such, for instance, as the exploration of the 


218 Lull—Development of Vertebrate Paleontology. 


Antarctic continent, gave promise of further high attain- 
ment, when his hand was arrested by death. 


SUMMARY. 


It is not surprising that American vertebrate paleontol- 
ogy has arisen to so high a plane, when one considers the 
material at its disposal. Having a vast and virgin field 
for exploration, a sufficient number of collectors, some of 
whom have devoted much of their lives to the work, and 
a refinement of technique that permitted the preservation 
of the fragmental and ill conserved as well as the finer 
specimens, the results could hardly have been otherwise. 
Thus it has been possible to secure material almost 
unique throughout the world for extent, for complete- 
ness, and for variety. To this must be added a certain 
American daring in the matter of the restoration of miss- 
ing portions, both of the individual bones and of the 
skeleton as a whole, such as European conservatism will 
not as a rule permit. This work has for the most part 
been done after the most painstaking comparison and 
research and is highly justified in the accuracy of the 
results, which render the fabric of the skeleton much 
more intelligible, both to the scientist and to the layman. 
Material once secured and prepared is then mounted, 
and here again American ingenuity has accomplished 
some remarkable results. Some of the specimens thus 
mounted are so small and delicate as to require holding 
devices comparable to those for the display of jewels; 
yet others—huge dinosaurs the bones of which are enor- 
mously heavy, but so brittle that they will not bear even 
the weight of a process unsupported—require a care- 
fully designed and skilfully worked out series of supports 
of steel or iron which must be perfectly secure and at the 
same time as inconspicuous as possible. And of late the 
lifelike pose of the individual skeleton has been aug- 
mented by the preparation of groups of several animals 
which collectively exhibit sex, size, or other individual 
variations and the full mechanics of the skeleton under 
the varying poses assumed by the creature during life. 


The work of further restoration has been rendered pos- 


sible through comparative anatomical study, enabling us 
to essay restorations in entirety by means of models and 
drawings, clothing the bones with sinews and with flesh 
and the flesh with skin and hair, if such the creature 


Lull—Development of Vertebrate Paleontology. 219 


bore; while the laws of faunal coloration have permitted 
the coloring of the restoration in a way which if not the 
actual hue of life is a very reasonable possibility. 

Thus the American paleontologists have blazed a trail 
which has been followed to good effect by certain of their 
Old World colleagues. 

With such means and methods and such material avail- 
able, it is again not surprising that American paleontology 
has furnished more and more of the evidences of evolu- 
tion, and disclosed to the eyes of scientists animal rela- 
tionships which were undreamed of by the systematist 
whose research dealt only with the existing. It has also 
explained some vexatious problems of animal distribution 
and of extinction, and has connected up cause and effect 
in the great evolutionary movements which are recorded. 

The results of systematic research have added hosts of 
new genera and species and of families, but of orders 
there are relatively few. Nevertheless a number, 
especially among reptiles and mammals, have come to 
hght as the fruits of American discovery. But aside 
from the dry cataloguing of such groups, the American 
systematists have worked out some very remarkable phy- 
logenies and have thus clarified our vision of animal 
relationships in a way which the recent zoologist could 
never have done. In this connection, the Permian ver- 
tebrates, which have been collected and studied with 
amazing success, principally by Williston and Case, 
should be mentioned, although the work is yet incom- 
plete. Some of these forms are amphibian, others rep- 
tilian, vet others of such character as to link the two 
classes as transitional forms. Of the Mesozoic reptiles, 
a very remarkable assemblage has come to light, in a 
degree of perfection unknown elsewhere. These are dino- 
saurs, of which several phyla are now known; carnivores 
both great and small, some of the latter being actually 
toothless; Sauropoda, whose perfection and dimensions 
are incomparable except for those found in East Africa; 
and predentates, armored, unarmored, and horned, the 
last exclusively American. The unarmored trachodonts 
are now known in their entirety, for not only has our 
West produced articulated skeletons but mummified ecar- 
casses whose skin and other portions of their soft 
anatomy are represented, and which are thus far without 
a parallel elsewhere in the world. Other reptilian 
groups are well known, notably the Triassic ichthyosaurs, 


220 Lull—Development of Vertebrate Paleontology. 


and the mosasaurs and plesiosaurs of the Kansas chalk. 
The last formation has also produced toothed birds, 
Hesperornis and Ichthyorms, which again are absolutely 
unique. 

But it is in the mammalian class that the phylogenies 
become so highly complete and of such great importance 
as evolutionary evidences, for nowhere else than in our 
own West have such series been found as the Dinocerata 
and creodonts among archaic forms, the primitive 
primates from the Eocene, the carnivores such as the 
dogs and cats and mustellids, but especially the hoofed 
orders such as the horses. Of these hoofed orders, the 
classic American series of horses is complete, that of - 
the camels probably no less so, while much is known of 
the deer and oreodonts, the last showing several parallel 
phyla, and of the proboscideans, which while having their 
pristine home in the Old World nevertheless soon sought 
the new where their remains are found from the Miocene 
until their final and apparently very recent extinction. 
These creatures show increase of bulk, perfection of feet 
and teeth, development of various weapons, horns and 
antlers, which may be studied in their relationship with 
the other organs to make the evolving whole, or their 
evolution may be traced as individual structures which 
have their rise, culmination, and sometimes their senile 
atrophy in a way comparable to that of the representa- 
tives of the order as a whole. Thus, for example, 
Osborn has traced the evolution of the molar teeth, and 
Cope of the feet, while Marsh has shown that brain devel- 
opment runs a similar course and that its degree of per- 
fection within a group is a potent factor for survival. 

As a student of evolution, the paleontologist sees 
things in a very different light from the zoologist. The 
latter is concerned largely with matters of detail—with 
the inheritance of color or of the minor and more super- 
ficial characteristics of animals—and the period of 
observation of such phenomena is of necessity brief | 
because of the mortality of the observer. Whereas the 
paleontologist has a perspective which the other lacks, 
since for him time means little in the terms of his own 
life, and he can look into the past and see the great and 
fundamental changes which evolution has wrought, the 
rise of phyla, of classes, of orders, and he alone can see 
the orderliness of the process and sense the majesty of 
the laws which govern it. 


Lull—Development of Vertebrate Paleontology. 221 


INFLUENCE OF THE AMERICAN JOURNAL OF SCIENCE. 

The influence of the American Journal of Science as a 
medium for the dissemination of the results of vertebrate 
research has been in evidence throughout this discussion, 
but it were well, perhaps, to emphasize that service more 
fully. The Journal was, as we have seen, the chief outlet 
for Professor Marsh’s research, for there were published 
in it during his lifetime no fewer than 175 papers descrip- 
tive of the forms which he studied, as well as a great part 
of the material in the published monographs. As Marsh 
left very few manuscript notes, the importance of these 
frequent publications in thus setting forth much that he 
thought and learned concerning the material is very 
great indeed. The combined titles of all other authors in 
the Journal in this line of research for the century of its 
life fall far short of the number produced by Marsh 
alone, as they include 136 all told, but the range of sub- 
jects is highly representative of the entire field of verte- 
brate research. It should be borne in mind, moreover, 
that Leidy, Cope, and Osborn each had another medium 
of publication, which of course is true of other workers 
in the great museums such as the American, National, 
and Carnegie, all of which issue bulletins and quarto 
publications for the purpose of disseminating the work 
of their staff. Many of the earlier announcements of the 
discovery of vertebrate relics appeared in the Journal, as 
did practically all the literature of the science of fossil 
footprints (ichnology), except of course the larger 
quartos of Hitchcock and Deane. Of the footprint 
papers by Hitchcock, Deane, and others, there were no 
fewer than thirty-two, with a number of additional com- 
munications on attendant phenomena bones and plants. 

Up to 1847, except for a few foreign announcements, 
the Journal published almost exclusively on eastern Amer- 
ican paleontology, the only exception being a notice of 
bones from Oregon by Perkins in 1842. In 1847 came the 
announcement of a western ‘‘Palewothere’’ by Prout, 
which marked the beginning of the researches of Leidy 
and others in the Bad Lands of the great Nebraska 
plains. The Journal thenceforth published paper after 
paper on forms from all over North America, and on all 
aspects of our science: discovery, systematic descrip- 
tion, faunal relationships, evolutionary evidences—thus 
showing that breadth and catholicity which has made it 
so great a power in the advancement of science. 


222 TL. V. Porsson—Rise of Petrology as a Science. 


Art. VII.—The Rise of Petrology as a Science; 
by Louis V. Pirsson. 


This chapter is intended to present a brief sketch of the 
progress of the science of petrology from its early begin- 
nings down to the present time. The field to be covered 
is so large that this can be done only in broadest outline, 
and it has therefore been restricted chiefly to what has 
been accomplished in America. Although the period 
covered by the life of this Journal extends backward for 
a century it is, however, practically only within the last 
fifty years that the rocks of the earth’s crust have been 
made the subject of such systematic investigation by 
minute and delicately accurate methods of research as to 
give rise to a distinct branch of geologic science. It is 
not intended of course to affirm by this statement that the 
broader features of the rocks, especially those which may 
be observed in the field and which concern their relations 
as geological masses, had not been made the object of 
inquiry before this time, since this is the very foundation 
of geology itself. Moreover, a certain amount of investi- 
gation of rocks, as to the minerals of which they were 
composed, the significance of their textures, and their 
chemical composition, had been carried out, concomitant 
with the growth from early times of geology and min- 
eralogy. Thus, in 1815, Cordier by a process of washing 
separated the components of a basalt and by chemical 
tests determined the constituent minerals. At the time 
this Journal was founded, and for many years following, 
the genesis of rocks, especially of igneous rocks, was a 
subject of inquiry and of prolonged discussion. The 
aid of the rapidly growing science of chemistry was 
invoked by the geologists and analyses of rocks were 
made in the attempt to throw light on important ques- 
tions. It is remarkable, also, how keen were the obser- 
vations that the geologists of those days made upon the 
rocks, as to their component minerals and structures, 
aided only by the pocket lens. Many ideas were put for- | 
ward, the essentials of which have persisted to the pres- 
ent day and have become interwoven into the science, 
whereas others gave rise to contentions which have not 
vet been settled to the satisfaction of all. At times in 


L.V. Pirsson—Rise of Petrology as a Science, 228 


these earlier days the microscope was called into use to 
help in solving questions regarding the finer grained 
rocks, but this employment, as Zirkel has shown, was 
merely incidental, and no definite technique or purpose 
for the instrument was established. 

On the other hand, the fact that up to the middle of the 
last century a large store of information relating to the 
occurrence of rocks, and to the mineral composition of 
those of coarser grain, and somewhat in respect to their 
structure, had been accumulated, caused attempts in one 
way or another to find means of coordinating these data 
and to produce classifications, such as those of Von Cotta 
and Cordier. The history of these attempts at classifi- 
cation, before the revelations made by the use of the 
microscope had become general, has been admirably 
reviewed by Whitman Cross! and need not be further 
enlarged upon here. 

That a considerable amount of work was done along 
chemical lines also is testified to by the publication of 
Roth’s Tabellen in 1861, in which all published analyses of 
rocks up to that date were collected. What was accom- 
plished during this period was done chiefly on the con- 
tinent of Europe, and little attention had been paid to the 
subject of rocks either in America or in Great Britain— 
even so late as 1870 Geikie remarks, as referred to by 
Cross,? that there was no good English treatise on 
petrography, or the classification and description of 
rocks. In this country still less had been accomplished, 
interest being almost wholly confined to the vigorous and 
erowing sciences of geology and mineralogy. This was 
natural, for mineralogy is the chief buttress on which the 
structure of petrology rests and must naturally develop 
first, especially in a relatively new and unexplored 
region, whose mineral resources first attract attention. 
The geologists in carrying out their studies also observed 
the rocks as they saw them in the field and made inci- 
dental reference to them, but investigations of the rocks 
themselves -was very little attempted. An inspection of 
the first two series of this Journal shows relatively little 
of importance in petrology published in this country; 
a few analyses of rocks, occasional mention of mineral 
composition, of weathering properties, and notices of 


_ 1¥For references, see the Bibliography at the end of this chapter. 


224 L.V.Pirsson—Rise of Petrology as a Science. 


methods of classification proposed by French and Ger- 
man geologists nearly exhaust the list. 


INTRODUCTION OF THE MICROSCOPE. 


The beginnings of a particular branch of science are 
generally obscure and rooted so imperceptibly in the 
foundations on which it rests that it is difficult to point 
to any particular place in its development and say that 
this is the start. There are exceptions of course, like the 
remarkable work of Willard Gibbs in physical chemistry, 
and it may chance that the happy inspiration of a single 
worker may give such direction to methods of investiga- 
tion as to open the gates into a whole new realm of 
research, and to thus create a separate scientific field, as 
happened i in Radiochemistry. 

This is what occurred in petrology when Sorby in 
England, in 1858,3 pointed out the value of the micro- 
scope as an instrument of research in geologic investiga- 
tions, and demonstrated that its employment in the study 
of thin sections of rocks would yield information of the 
highest value. Others beside Sorby had made use of the 
microscope, as pointed out by Zirkel,* but, as he indi- 
cates, no one before him had recognized its value. Dur- 
ing the next ten years or so, however, its recognition was 
very slow and the papers published by Sorby himself 
were mainly concerned in settling very special matters. 

As Williams’ has suggested, the greatest service of 
Sorby was, perhaps, his instructing Zirkel in his ideas 
and methods, for the latter threw himself whole-heart- 
edly into the study of rocks by the aid of the microscope 
and his discoveries stimulated other workers in this field 
in Germany, his native country, until the dawning science 
of petrology began to assume form. A further step for- 
ward was taken in 1873 in the appearance of the text- 
books of Zirkel® and Rosenbusch’ which collated the 
knowledge which had been gained and furnished the 
investigator more precise methods of work. It is diffi- 
cult for the student of to-day to realize how much had 
been learned in the interval and, for that matter, how 
much has been gained since 1873, without. an inspection 
of these now obsolete texts. In 1863, Zirkel, who was 
then at the beginning of his work, said in his first paper 
presented to the Vienna Academy of Sciences® that if he 


L. V. Pirsson—Rise of Petrology asaScience. 225 


confined himself chiefly to the structure of the rocks 
investigated and of their component minerals, and stated 
little as to what these minerals were, the reason for that 
was because ‘‘although the microscope serves splendidly 
for the investigation of the former relations, it promises 
very little help for the latter. Labradorite, oligoclase 
and orthoclase, augite and hornblende, minerals whose 
recognition offers the most important problems in 
petrography, in most cases cannot be distinguished from 
one another under the microscope.’’ How little could 
Zirkel have foreseen, at this time, less than forty years 
later, that not only could labradorite be accurately 
determined in a rock-section, but that in a few minutes by 
the making of two or three measurements on a properly 
selected section, its chemical composition and the erys- 
-tallographic orientation of the section itself could be 
determined! 


THe THin SECTION. 


_Before going further we may pause here a moment to 
consider the origin and development of the thin section, 
without which no progress could have been made in this 
field of research. When we reflect upon the matter, it 
seems a marvelous thing indeed that the densest, blackest 
rock can be made to yield a section of the 1/1000 of an 
inch in thickness, so thin and transparent that fine print- 
ing can be easily read through it, and transmitting light 
so clearly that the most high-powered objectives of the 
microscope can be used to discern and study the minutest 
structures it presents with the same capacity that they 
can be employed upon sections of organic material pre- 
pared by the microtome. This is no small achievement. 

The first thin sections appear to have been prepared in 
1828 by William Nicol of Edinburgh, to whom we owe the 
prism which carries his name. He undertook the making 
of sections from fossil wood for the purpose of studying 
its structure. The method he developed was in principle 
the same as that employed to-day, where machinery is 
not used; that is, he ground a flat smooth surface upon 
one side of a chip of his petrified wood, then cemented 
this to a bit of glass plate with Canada balsam, and 
ground down the other side until the section was suffi- 
ciently thin. This method was used by others for the 
study of fossil woods, coal, ete., but it was not applied to 


Am. Jour. Sct.—FourtH Sreries, Vou. XLVI, No. 271.—Juty, 1918. 
8 


226 L.V. Pirsson—Rise of Petrology as a Science. 


rocks until 1850, when Sorby used it for investigating a 
caleareous grit. Oschatz, in Germany, also about this 
time independently discovered the same method. A fur- 
ther advance was made in melting the cement, floating off 
the slice, and transferring it to a suitable object-glass 
with cover, a process still employed by many; though 
most operators now cement the first prepared surface of 
the rock chip directly to the object-glass, and mount the 
section without transferring it. 

Next came the use of machinery to save labor in grind- 
ing, and another step was made in the introduction of the 
saw, a circular disk of sheet iron whose edge was fur- 
nished with embedded diamond dust. This makes it 
possible to cut relatively thin slices with comparative 
rapidity, but the final grinding which requires experience 
and skill must still be done by hand. Carborundum has 
also largely replaced emery. The skill and technique of 
preparers has reached a point where sections of rocks of 
the desired thinness (0-001 inch), and four or five inches 
square have been exhibited. 


THe ERA oF PETROGRAPHY. 


In these earlier days of the science, as noted above, 
great difficulty was at first experienced in the recognition 
of the minerals as they were encountered in the study of 
rocks under the microscope. At that time the chemical 
composition and outward crystal form of minerals were 
relatively much better known than their physical and, 
especially, their optical properties and constants. Some 
beginnings in this had been made by Brewster, Nicol, and 
other physicists, and the mineralogists had commenced 
to study minerals from this viewpoint. Especially 
Des Cloiseaux had devoted himself to determining the 
optical properties of many minerals, and the writer, 
when a student in the laboratory of Rosenbusch in 1890, 
well recalls the tribute that he paid to the work of 
Des Cloiseaux for the aid which it had afforded him in his 
earlier researches in petrography. : 

The twenty years following the publication of the © 
texts of Rosenbusch and Zirkel may be characterized as 
the era of microscopical petrography. A distinction is 
drawn here between the latter word and petrology, a 
distinction often overlooked, for petrography means lt- 
erally the description of rocks, whereas petrology denotes 


L.V. Pirsson—Rise of Petrology asa Science. 227 


the science of rocks. As time passed the broader and 
more fundamental features of rocks, especially of igneous 
and metamorphic rocks, in addition to their mineral 
constitution, were more studied and gained greater recog- 
nition, petrography gradually became a department of 
the larger field of petrology—the science of to-day. 

The use of the microscope, as soon as the method 
became more generally understood, opened up so vast a 
field for investigation that at first the study and descrip- 
tion of the rocks seemed of prime importance. This was 
natural, for hitherto the finer grained rocks had for the 
most part defied any adequate elucidation and here was a 
key which enabled one to read the cipher. <A flood of lit- 
erature upon the composition, structure, and other char- 
acters of rocks from all parts of the world began to 
appear in ever increasing volume. The demands of the 
petrographers for a greater and more accurate knowledge 
of the physical and optical constants of minerals stimu- 
lated this side of mineralogy, and increasing attention 
was given to investigations in this direction. No definite 
line between the two closely related sciences could be 
drawn, and a large part of the work published under the 
heading of petrography could perhaps be as well, or 
better, described under the title of micro-mineralogy. 
To some, in truth, the rocks presented themselves simply 
as aggregates of minerals, occurring in fine grains. 

The work of the German petrographers attracted 
attention and drew students from all parts of the world 
to their laboratories, especially to those of Zirkel and 
Rosenbusch. The great opportunities, facilities, and 
freedom for work which the German universities had 
long offered to foreign students of science naturally 
encouraged this. In France a brilliant school of petrolo- 
gists, under the able leadership of Michel-Lévy and 
Fouqué, had arisen whose work has been continued by 
Barrois, Lacroix and others, but the rigid structure of 
the French universities at that period did not permit 
of the offering of great inducements for the attendance 
of foreign students. The work of the French petrog- 
raphers will be noticed in another connection. 

In Great Britain, the home of Sorby, the new science 
progressed at first slowly, until it was taken up by All- 
port, Bonney, Judd, Rutley, and others. In 1885 the 
evidence of the advance that had been made and of the 


228) =L.V. Pirsson—Rise of Petrology as a Science. 


firm basis on which the new science was now placed 
appeared in Teall’s great work, ‘‘ British Petrography,’’ 
which marked an epoch in that country in petrographic 
publication. This work was of importance also in 
another direction than that of descriptive petrography, 
in that it contains valuable suggestions for the applica- 
tion of the principles of modern physical chemistry in 
solving the problems of the origin of igneous rocks. In 
it, as in the publications of Lagorio, we see the passage of 
the petrographic into the petrologic phase of the science. 

The earliest publication in America of the results of 
microscopic investigation of rocks that the writer has 
been able to find is by A. A. Julien and C. E. Wright, 
chiefly on greenstones and chloritic schists from the 
iron-bearing regions of upper Michigan.® Naturally, it 
was of a brief and elementary character. In 1874 E. S. 
Dana read a paper before the American Association for 
the Advancement of Science on the result of his studies 
on the ‘‘Trap-rocks of the Connecticut valley,’’ an 
abstract of which was published in this Journal.’° 
Meanwhile Clarence King, in charge of the 40th Parallel 
survey, feeling the need of a systematic study of the 
erystalline rocks which had been encountered, and finding 
no one in this country prepared to undertake it, had 
induced Zirkel to give his attention to this task. The 
result of this labor appeared in 1876 in a fine volume™ 
which attracted great attention. In the same year 
appeared also petrographical papers by J. H. Caswell,’” 
KH. S. Dana!? and G. W. Hawes. The latter devoted 
himself almost entirely to this field of research and may 
thus, perhaps, be termed the earliest of the petrog- 
raphers in this country. His work, ‘‘The Mineralogy 
and Lithology of New Hampshire,’’ issued in 1878 as one 
of the reports of the State Survey under Prof. C. H. 
Hitchcock, was the first considerable memoir by an 
American. This was followed by various papers, one on 
the ‘‘Albany Granite and its contact phenomena,’”° 
being of especial interest as one of the earliest studies of 
a contact zone, and in the fullness of methods employed — 
in attacking the problem forecasting the change to 
the petrology era. 

During the ten years following, or from 1880 to 1890, 
the new science of petrography flourished and grew 
exceedingly. Many young geologists abroad devoted 


L.V. Pirsson—Rise of PetrologyasaScience. 229 


themselves to this field of research and the store of 
accumulated knowledge concerning rocks from all parts 
of the world, and their relations grew apace. The work 
of Teall has been noticed and among others might be 
mentioned the name of Brogger, whose first contribu- 
tion’® in this field gave evidence that his publications 
would become classics in the science. 

In America there appeared in this period a number of 
eager workers, trained in part in the laboratories of 
Rosenbusch and Zirkel, whose researches were destined 
to place the science on the secure footing in this country 
which it occupies to-day. Among the earlier of these may 
be mentioned Whitman Cross, R. D. Irving, J. P. Iddings, 
G. H. Williams, J. F. Kemp, J. S. Diller, B. K. Emerson, 
M. EK. Wadsworth, G. P. Merrill, N. H. Winchell, and 
F.. D. Adams in Canada. Others were added yearly to 
this group. As a result of their work a constantly grow- 
ing volume of information about the rocks of America 
became available, and one has only to examine the files 
of this and other journals and the listed publications of 
the National and State Surveys to appreciate this. 

In this Journal, for example, we may refer to papers" 
by Emerson on the Deerfield dike and its minerals, and 
on the occurrence of nephelite syenite at Beemersville, 
N. J.; to various interesting articles by Cross on lavas 
from Colorado and the pneumatolytic and other min- 
erals associated with them; to important papers by 
Iddings on the rocks of the voleanoes of the Northwest, 
and those of the Great Basin, to primary quartz in 
basalt, and the origin of lithophyse; to the results of 
researches by G. H. Williams on the rocks of the Cort- 
landt series, and on peridotite near Syracuse, N. Y.; to 
papers by Diller on the peridotites of Kentucky, and 
recent voleanic eruptions in California; to articles by 
R. D. Irving on the copper-bearing and other rocks of the 
Lake Superior region, and to Kemp on dikes and other 
eruptives in southern New York and northern New 
Jersey. Other publications would greatly extend this 
list. | | 


THe Perrouocic ERA. 


As the chief facts regarding rocks, especially igneous 
rocks, as to their mineral and chemical composition, their 
structure and texture and the limits within which these 


230 DL. V. Pirsson—Rise of Petrology as a Science. 


are enclosed, became better known; and the relations, 
which these bear to the associations of rocks and their 
modes of occurrence, began to be perceived, the science 
assumed a broader aspect. The perception that rocks 
were no longer to be regarded merely as interesting 
assemblages of minerals, but as entities whose charac- 
ters and associations had a meaning, increased. More 
and better rock analyses stimulated interest on the 
chemical side and this and the genesis of their minerals 
led to a consideration of the magmas and their fune- 
tions in rock-making. The fact that the different kinds 
of rocks were not scattered indiscriminately, but that 
different regions exhibited certain groupings with com- 
mon characters, was noticed. These features led to 
attempts to classify igneous rocks on different lines from 
those hitherto employed, and to account for their origin 
on broad principles. In other words, the descriptive 
science of petrography merged into the broader one of 
petrology. No exact time can be set which marks this 
passage, since the evolution was gradual. Yet for this 
country, in reviewing the literature, for which the suc- 
cessive issues of the ‘‘Bibliography of North American 
Geology’’ published by the U. S. Geological Survey has 
been of the greatest value; the writer has been struck by 
the fact that in the first volume containing the index of 
papers down to and including 1891, the articles on sub- 
jects of this nature are listed under the heading of 
petrography, whereas in the second volume (1892-1900) 
they are grouped under petrology and the former head- 
ing is omitted. A justification for this is found in 
examining the list of publications and noting their char- 
acter. With some reason, therefore, the beginning of 
this period may be placed as in the early years of this 
decade. Furthermore, it was at this time that the great 
work of Zirkel'® began to appear, which sums up so com- 
pletely the results of the petrographicera. Rosenbusch’® 
was formulating more definitely his views on the division 
of rocks into magmatic groups, as displayed by their 
associations in the field, and using this in classification; — 
an idea which, appearing first in the second edition of his 
‘‘Physiographie der massigen Gesteine,’’ finds fuller 
development in the third and last editions of this work. 
In this country Iddings?°® published an important paper, 
in which the family relationships of igneous rocks and 


L.V. Pirsson—Rise of Petrology asa Science. 231 


the derivation of diverse groups from a common magma 
by differentiation are clearly brought out. The funda- 
mental problems underlying the genesis of igneous rocks 
had now been clearly recognized, and with this recogni- 
tion the science passed into the petrologic phase. 
Brogger*! also had ascribed to the alkalic rocks of South 
Norway a common parentage and had pointed out their 
regional peculiarities. 

From this time forward an attempt may be noted to find 
an analogy between rocks and the forms of organic life 
and to apply those principles of evolution and descent, 
which have proved so fruitful in the advancement of the 
biological sciences, to the genesis and classification of 
igneous rocks. This, perhaps, has on the whole been 
more apparent than real, in the constant borrowing of 
terms from those sciences to express certain features and 
relationships observed, or imagined, to obtain among 
rocks. Nevertheless, the perception of certain relations 
which we owe so largely to Rosenbusch and to Brogger?? 
has proved of undoubted value in furnishing a stimulus 
for the investigation of new regions, and in affording 
indications of what the petrologist shouid anticipate in 
his work. 

Thus, the labors of the men previously mentioned, with 
those of Bayley, Bascom, Cushing, Daly, Lane, Lawson, 
Lindgren, Pirsson, J. F. Williams, Washington, and 
others, have thrown a flood of light upon the igneous 
rocks of this continent, and has made it possible to draw 
many broad generalizations concerning their origin and 
distribution. Thus, the differentiated laccoliths of Mon- 
tana?* have been of service in affording clear examples of 
the process of local differentiation. Many papers pub- 
lished in this Journal during the last twenty years show 
this evolution and growth of petrological ideas. The 
eontributions from American sources during this later 
period, and of which those in the Journal form a consid- 
erable fraction, have indeed been of great weight in 
shapmeg the development and future of the science. 

By referring to the files of the Journal, it will be seen 
that they cover a continually widening range of subjects 
concerning rocks, and articles of theoretical interest are 
more and more in evidence, along with those of a purely 
deseriptive character.2* Thus we find discussions by 
Becker on the physical constants of rocks, on fractional 


232 DL. V. Pirsson—Rise of Petrology as a Science. — 


crystallization, and on differentiation; by Cross on 
classification; by Adams on the physical properties of 
rocks; by Daly on the methods of igneous intrusion; by 
Wright on schistosity; by Fenner on the crystallization 
of basaltic magma; by Bowen on differentiation by 
crystallization; by the writer on complementary rocks 
and on the origin of phenocrysts; by Smyth on the origin 
of alkalic rocks; by Murgoci on the genesis of riebeckite 
rocks; and by Barrell on contact-metamorphism. These 
may serve as examples, selected almost at random, from 
the files of the Journal, and we find with them articles 
descriptive of the petrology of many particular regions, 
which often contain also matter of general interest and 
importance, such as papers by Lindgren on the grano- 
diorite and related rocks of the Sierra Nevada; by 
Ransome on latite; by Cross on the Leucite Hills; by 
Hague on the lavas of the Yellowstone Park; by Pogue 
on ancient volcanic rocks from North Carolina; by War- 
ren on peridotites from Cumberland, R. I.; on sandstone 
from Texas by Goldman; and on the petrology of vari- 
ous localities in central New Hampshire by Washington 
and the writer. Such a lst could of course be much 
extended and other papers of importance be cited, but 
enough has been said to indicate how important a reposi- 
tory of the results of petrologic research the Journal has 
been and continues to be. 

In thus looking backward over the list of active 
workers we are involuntarily led to pause and reflect 
how great a loss American petrology has sustained in 
the premature death of some of its most brilliant and 
promising exponents; it is only necessary to recall the 
names of R. D. Irving, G. H. Williams, G. W. Hawes, 
J. F. Williams and Carville Lewis, to appreciate this. 

The store of material gathered during these years has 
led to the publication of extensive memoirs, in which the 
science is treated not from the older descriptive side, but 
from the theoretical standpoint and of classification.?° 
In these works strong divergencies of views and opinions 
are observed, which is a healthy sign in a developing 
seclence. 

It should be also noted that along with this evolution 
on the theoretical side there has been a constant improve- 
ment in the technique of investigating rocks. It is only 
necessary to compare the older handbooks of Zirkel and 


L.V. Porsson—Rise of Petrology asa Science. 288 


Rosenbusch with the many modern treatises on petro- 
eraphic methods to be assured of this.2° It is due on the 
one hand to the vast amount of careful work which has 
been done in accurately determining the physical con- 
stants of rock-minerals* and in arranging these for their 
determination microscopically, as in the remarkable 
studies on the feldspars by Michel-Lévy, and on the other 
in researches on the apparatus employed, and in conse- 
quent improvements in them and in ways of using them, 
as exemplified in the delicately accurate methods intro- 
duced by Wright.27 The development of the microscope 
itself as an instrument of research in this field and in 
mineralogy deserves a further word in this connection. 
The first step toward making the ordinary microscope of 
special use in this way was taken by Henry Fox Talbot 
of England, when he introduced in 1834 the employment 
of the recently invented nicol prisms for testing objects 
in polarized light. The modern instrument may be said 
to date from the design offered by Rosenbusch in 1876. 
Since that time there have been constant improvements, 
almost year by year, until the instrument has become one 
of great precision and convenience, remarkably well 
adapted for the work it is called upon to perform, with 
special designs for various kinds of use, and an almost 
endless number of accessory appliances for research in 
different branches of mineralogy and crystallography, as 
well as in petrography proper.”® This also calls to mind 
the fact that for the convenience of those who are not able 
to use the microscope special manuals of petrology have 
been prepared in which rocks are treated from the 
megascopic standpoint.?? 


MetTAMORPHIC Rocks. 


In this connection the metamorphic rocks should not 
be forgotten. They afford indeed the most difficult 
problems with which the geologist has to deal; every 
branch of-geological science may in turn be called upon to 
furnish its quota for help in solving them. Under the 


* We may mention here, for example, the work in mineralogy of Pen- 
field, noticed in the accompanying chapter on mineralogy. In addition to 
the accurate determination of the composition and constants of many 
minerals, some of which have importance from the petrographic standpoint, 
we owe to him more than anyone the recognition of fluorine and hydroxyl 
in a variety of species, and thereby the perception of their pneumatolytie 
origin. His papers have been published almost entirely in this Journal. 


234 DL. V. Pirsson—Rise of Petrology as a Science. 


attack of careful, accurate and persistent work in the 
field, under the microscope and in the chemical labora- 
tory, with the aid of the garnered knowledge in petrol- 
ogy, stratigraphy, physiography, and other fields of 
eeologic science, their mystery has in large part given 
way. The inaucural work of Lehmann, Lossen, Barrois, 
Bonney, Teall, and other European geologists, was par- 
alleled in America by that of R. D. Irving, owing to whose 
efforts the Lake Superior region became the chief place 
of study of the metamorphic rocks in this country. 
Irving soon obtained the assistance of G. H. Williams, 
who had been engaged in the study of such rocks, and the 
latter published a memoir on the greenstone schist areas 
of Menominee and Marquette in Michigan®® which will 
always remain one of the classics in the literature of 
metamorphic rocks. Irving’s own contributions to 
petrology, though valuable, were cut short by his 
untimely death, but the study of this region under the 
direction of his associate and successor, C. R. Van Hise, 
with his co-laborors, has yielded a mass of information 
of fundamental importance in our understanding of met- 
amorphism and the crystalline schists. Its fruitage 
appears in the memoir by Van Hise*! which is the author- 
itative work of reference on metamorphism, and in 
various publications by him and his assistants, Bayley, 
Clements, Leith, and others. The work of the Canadian 
geologists, and of Kemp, Cushing, Smyth and Miller in 
the Adirondack region, should also be mentioned i Im con- 
nection with this field of petrology. 


CHEMICAL ANALYSES OF ROCKS. 


It has been previously pointed out that, as the science 
of petrology grew, chemical investigations of rocks in 
bulk were undertaken. The object of such analyses was 
to obtain on the one hand a better control over the 
mineral composition and on the other to gain an idea of 
the nature of the magmas from which igneous rocks had 
formed. The earliest analysis of an American rock of 
which I ean find record is of a ‘‘wacke’’ by J. W. Webster | 
given in the first volume of this Journal, page 296, 1818. 

During the next 40 years a few occasional analyses 
were undertaken by American chemists, by C. T. Jackson, 
T. Sterry Hunt, and others. In 1861, Justus Roth pub- 
lished the first edition of his Tabellen, in which he 
included all analyses which had been made to that date 


L. V. Pirsson—Rise of Petrology as aScience. 235 


and which he considered were worthy of preservation. 
Although, naturally, from the status of analytical chem- 
istry up to that time, most of these would now be con- 
sidered rather crude, the publication of the work was of 
great service and marked an epoch in geochemistry. In 
these tables Roth lists four analyses of American igneous 
rocks, two from the Lake Superior region by Jackson 
and J. D. Whitney and two by European chemists, one of 
whom was Bunsen. The material of the last two was a 
‘‘dolerite’’ and the same locality is given for each— 
‘‘Sierra Nevada between 38° and 41°’? which was prob- 
ably considered quite precise for western America in 
those days. 

From these feeble beginnings the forward progress of 
petrology on the chemical side in this country has been 
a Steady one until its development has reached the point 
which will be indicated in what follows. 

The collection of material by the various State surveys 
and by those initiated by the National Government led to 
an increasing number of rocks being analyzed during the 
petrographic period. These became also increasingly 
good in quality, like those published by G. W. Hawes in 
his papers.. When, however, chemists were appointed to 
definite positions on the staffs of the Government surveys 
and especially when, after the organization of the U. S. 
Geological Survey in 1879, a general central laboratory 
was founded in 1883 with F. W. Clarke in charge, 
then a new era in the chemical investigation of rocks may 
be said to have started. In this connection should be 
mentioned the work of W. F. Hillebrand, who set a stand- 
ard of accuracy and detail in rock analysis which had not 
hitherto been attempted. As a consequence of his accu- 
rate and thorough methods and results the mass of 
analyses performed by him and his fellow chemists in 
this laboratory affords us the greatest single contribu- 
tion to chemical petrology which has been made. Up to 
January, 1914, the report of Clarke*®? lists some 8000 
analyses of various kinds made in this laboratory for 
geologic purposes. Nearly everywhere also a great 
improvement in the quality of rock-analyses is to be 
noted, and in the manuals of Hillebrand** and Washing- 
ton*+ the rock analyst has now at his command the 
methods of a greatly perfected technique which should 
insure him the best results. 

Roth’s Tabellen have been previously mentioned; sev- 


236 LL. V. Pirsson—Rise of Petrology as a Science. 


eral supplements were published, but after his death a 
long interval elapsed before this convenient and useful 
work was again taken up by Washington®® and Ogann.°¢ 
A new edition of Washington’s Tables has recently been 
published, listing some 8600 analyses of igneous rocks 
made up to the close of 1913.37 

On the theoretical side also, where petrology passes 
into geology, the investigator of to-day will find a mass 
of most useful and accurate data well discussed in the 
modern representative of Bischof’s Chemical Geology— 
Clarke’s Data of Geochemistry.*® The advance on the 
chemical side, therefore, has been quite commensurate 
with that in the microscope as an instrument, and in the 
results obtained by it. 


PuHysico-CHEMICAL WORK. 


The study of geological results by experimental 
methods, which should gain information concerning the 
processes by which those results are caused, and the con- 
ditions under which they operate, has been from the 
earhest days of the developing science recognized as 
most important, and the record of the literature shows 
considerable was done in this direction. Experimental 
work in modern petrology may, however, be considered 
to date from 1882 when Fouqué and Michel-Lévy*® pub- 
lished the results of their extensive researches on the 
synthesis of minerals and rocks by pyrogeneous methods. 
The brilliant experiments of the French petrologists at 
once attracted attention, and since that time a consid- 
erable volume of valuable work has been done in this 
field by a number of men, among whom may be men- 
tioned Morozewicz,*? Doelter,*! Tamman,*? and Meunier.** 
As this work continued the results of the rapid advances 
made in physical chemistry began to be applied in this 
field with increasing value. To J. H. L. Vogt we owe a 
valuable series of papers,‘+ in which the formation of 
minerals and rocks from magmas is treated from this 
standpoint. Most important of all for the future of 
petrology has been the founding in Washington of the 
splendid research institution, the Carnegie Geophysical 
Laboratory, under the leadership of Dr. A. L. Day with 
its corps of trained physicists, chemists and petrologists, 
devoted to the solving of the problems which the progress 
of geological science raises. The publications of this 
institution (many of them published in the Journal) are 


L.V. Pirsson—Rise of Petrology asa Science. 237 


too numerous to be mentioned here; many of them 
treat successfully of matters of the greatest importance 
in petrology. This is an earnest of what we may hope in 
the future. The accumulation of the exact physical and 
chemical data, which is its aim, will serve as a necessary 
check to hypothetical speculation and bring petrology, 
and especially petrogenesis, in line with the other more 
exact sciences by furnishing quantitative foundations for 
its structure of theory to rest upon. 

While the achievements of this great organization seem 
to minimize the work of the individual investigator in 
this field, he may take heart by observing the important 
results on the strength of rocks under various condi- 
tions which have been obtained by Adams in recent years, 
data of wide application in theoretical geology. In this 
field also a special text has appeared in which the prin- 
ciples and acquired data are given.*® 


SUMMARY. 


In this brief retrospect, giving only the barest outlines 
and omitting from necessity much of importance, we have 
seen petrology grow from occasional crude experiments 
into a fully organized science in the last half century. It 
has to-day a well-perfected technique, a large volume 
of literature, texts treating of general principles, of 
methods of work, descriptive handbooks on the morph- 
ological side, and has attained general recognition as a 
field, which, though not large, is worthy of the concen- 
tration of intellectual endeavor. Like other healthy 
erowing organisms it has given rise to offshoots, and the 
sciences of metallography and of the micro-study of 
ore deposits, which are rapidly assuming form, have 
branched from it. 

What of the future? The old days of mostly descrip- 
tive work, and of theorizing purely from observed results, 
have passed. The science has entered upon the stage 
where work and theory must be continually brought into 
agreement with chemical, physical and mathematical 
laws and data, and in the application of these new prob- 
lems present themselves. As we climb, in fact, new hor- 
izons open to our view indicating fresh regions for 
exploration, for acquiring human knowledge and for 
our satisfaction. 


938 DL. V. Pirsson—Rise of Petrology as a Science. 


BIBLIOGRAPHY. 


1W. Cross, Jour. Geology, 10, 451, 1902. 

* Tbid., p. 45. 

’ Sorby, Quart. Jour. Geol. Soc., 14, 453, 1858. 

*Zirkel, Einfiihrung des Mikroskops in das mineralogisch-geologische 
Studium, 1881. 

° Williams, G. H., Modern Petrography, 1886. 

° Zirkel, Mikroskopische Beschaffenheit der Mineralien und Gesteine. 

7 Rosenbusch, Mikroskopische Physiographie der petrographisch wichtigen 
Mineralien. 

8 Zirkel, Mikroskopische Gesteinstudien, Sitzung vom 12 Marz, 1863. 

° Julien and Wright, Geol. Surv. of Michigan, 2, 1873. Appendices A 
and C. 

2 Dana, E. S., this Journal, 8, 390-392, 1874. 

1 Zirkel, Geological Exploration of the 40th Parallel; vol. VI, Micro- 
scopical Petrography. 

% Caswell, Microscopical Petrography of the Black Hills. U. 8S. Geog. 
and Geol. Surv. Rocky Mts. Rep. on Black Hills of Dakota, 469-527. The 
separate copies issued bear the imprint 1876; the complete report 1880. 

*% Dana, EH. S., Igneous Rocks in the Judith Mts. Rep. of Reconnaissance 
Carroll, Mont., to Yellowstone Park in 1875. Col. Wm. Ludlow, War 
Dept., Washington, 105-106. 

14 Hawes, G. W., Rocks of the Chlorite Formation, etc., this Journal, 11, 
122-126, 1876. Greenstones of New Hampshire, etc., ibid., 12, 129-137, 
1876. 

1° Hawes, G. W., this Journal, 21, 21-32, 1881. 

1° Brogger, Die silurischen Ktagen 2 und 3, Kristiania, 1882. 

7 The references for the papers alluded to, all of them in this Journal, 
are as follows: 

Emerson, 24, 195-202, 270-278, 349-359, 1882; 

, 23, 302-308, 1882. 

Cross, 27, 94-96, 1884; 31, 432-438, 1886; 39, 359-370, 1890; 41, 466- 
475, 1891; 23, 452-458, 1882. 

Iddings, 26, 222-235, 1883; 

, 27, 453-463, 1884; 
, 36, 208-221, 1888; 

———., 33, 36-45, 1887. 

Williams, 31, 26-41, 1886; 33, 135-144, 191-199, 1887; 35, 433-448, 
1888; 36, 254-259, 1888. 

———., 34, 137-145, 1887. 

Diller, 32, 121-125, 1886; 37, 219-220, 1889; 

———., 33, 45-50, 1887. 

Irving (26, 27-32, 321-322, 27, 130-134, 1883; 29, 358-359, 1885). 

Kemp (35, 331-332, 1888; 36, 247-253, 1888; 38, 130-134, 1889). 

8 Zirkel, Lehrbuch der Petrographie, 2d ed., 1893. 

* Hunter and Rosenbusch, Ueber Monchiquit, ete., Min. petr. Mitth., 11, 
445, 1890.. Rosenbusch, Ueber Structur und Class. der HEruptivgesteine, 
ibid., 12, 351, 1891. 

* Iddings, Origin of Igneous Rocks, Bull. Phil, Soc. Washington, 12, 
89-213, 1892. 

aap eee Mineralien der Syenit-pegmatit-gange, ete., Zs. Kryst., 16, 
1890. 

“—————, Basie Eruptive Rocks of Gran, Quart. Jour. Geol. Soe., 50, 
eee ; Grorudit-Tinguait-Serie, Vidensk. Skrift. 1 Math. nat. K1., No. 
4, 1894. 

“Weed and Pirsson, e.g. Shonkin Sag, this Journal, 12, 1-17, 1901. 

“The references for the articles mentioned (all in the Journal) are as 
follows: 

Becker, 46, 1893; 4, 257, 1897; 3, 21-40, 1897. 

Cross, 39, 657-661, 1915. 

Adams, 22, 95-123, 1906; 29, 465-487, 1910. 

Daly, 22, 195-216, 1906; 26, 17-50, 1908. 


L. V. Pirsson—Rise of PetrologyasaScence. 289 


Wright, 22, 224-230, 1906. 

Fenner, 29, 217-234, 1910. 

Bowen, 39, 175-191; 40, 161-185, 1915. 

Pirsson, 50, 116-121, 1895; 7, 271-280, 1899. 

Smyth, 36, 33-46, 1913. 

Murgoci, 20, 133-145, 1905. 

Barrell, 13, 279-296, 1902. 

Lindgren, 3, 301-314, 1897; 9, 269-282, 1900. 

Ransome, 5, 355-375, 1898. 

Cross, 4, 115-141, 1897. 

Hague, 1, 445-457, 1896. 

Pogue, 28, 218-238, 1909. 

Warren, 25, 12-36, 1908. 

Goldman, 39, 261-288, 1915. 

Washington and Pirsson, Belknap Mts., 20, 344-853, 1905; 22, 439-457, 
493-515, 1906. 

, Red Hill, 23, 257-276, 433-447, 1907. 
, Tripyramid Mt., 31, 405-431, 1911. 

= Quantitative Classification of Igneous Rocks, Cross, Iddings, Pirsson 
and Washington, Chicago, 1903. 

Petrogenesis, C. Doelter, Braunschweig, 1906. 

Igneous Rocks, vols. 1 and 2, J. P. Iddings, New York, 1909 and 1913. 

Problem of Volcanism, Iddings, New Haven, 1914. 

Natural History of Igneous Rocks, Alfred Harker, London, 1909. 

Igneous Rocks and their Origin, R. A. Daly, New York, 1914. 

*° Among these may be mentioned: 

Rosenbusch u. Wiulfing, Physiog. der petrog. wicht. Min., Stuttgart, 1905. 

Iddings, J. P., Rock-Minerals, 1st ed., New York, 1906. 

Johannsen, A., Manual of Petrographic Methods, New York, 1914. 

Winchell, N. H. and A. N., Elements of Optical Mineralogy, New York, 
1909. 

* Wright, Methods of Petrographice-Microscopic Research, Carnegie Inst., 
Washington, 1911, and various papers; many in this Journal. 

* Conf. Wright’s work quoted above and the various manuals previously 
mentioned. 

*° Kemp, Hand-book of Rocks, 3d ed., New York, 1904. Pirsson, Rocks 
and Rock-Minerals, New York, 1910. 

* Williams, G. H., U. S. Geol. Surv., Bull. 62, Washington, 1890. 

** Van Hise, Treatise on Metamorphism, U. S. Geol. Surv., Monograph 17. 

“FF. W. Clarke, U. S. Geol. Surv., Bull. 591, 1915. 

* Hillebrand, Analysis of Silicate and Carbonate Rocks, U. S. Geol. Surv., 
Bull. 422, 1910. 

** Washington, Chemical Analysis of Rocks, pp. 200, New York, 1910. 

* Td., Chemical Analyses of Igneous Rocks (1884-1900), U. S. Geol. Surv. 
Prof. Paper, No. 14, 1903. 

* Osann, Beitr. zu chem. Petrogr., II Teil. Anal. d. Eruptivgest., 1884- 
1900, Stuttgart, 1905. 
ee ene ton, Ibid., 2d ed., U. S. Geol. Surv., Prof. Paper 99, pp. 1216, 

ig 

* Clarke, U. S. Geol. Surv., Bull. 616, 1916. 
Fe Nas and Michel-Lévy, Synthese des Mineraux et des Roches, Paris, 

® Morozewicz, Exper. Untersuch. u. Bildung der Min. im Magma, Min. 
petr. Mitt., 18, 1898. 

“ Doelter, Synthetische Studien, N. Jahrb. Min. 1897, 1, 1-26. Allg. 
chem. Mineralogie, ete. 

“Tamman, Krystallisieren und Schmelzen, 1903. 

“St. Meunier, Les Méthodes de Synthése en Minéralogie, Paris, 1891. 

“Vogt, Mineralbildung in Smelzmassen, Christiania, 1892; Silikatschmelz- 
losungen, 1 and 2, 1903, 1904, and various other papers, esp. in Min. petr. 
Mitt., vols. 24 and 25, 1906. 

® H. HE. Boeke, Grundlagen der physikalisch-chemischen Petrographie, 
Berlin, 1915. 


b 


240 Ford—Growth of Mineralogy, 1818 to 1918. 


Art. VIIIL—The Growth of Mineralogy from 1818 to 
1918; by Wruuiam E. Forp. 


Mineralogy to-day would certainly be generally con- 
sidered one of the minor members of the group of the 
Geological Sciences. We commonly look upon it in the 
hght of an useful handmaiden, whose chief function is to 
serve the other branches, and we are inclined to forget 
that, in reality, mineralogy was the first to be recognized 
and, with considerable truth, might be claimed as the 
mother of all the others. Minerals, because of their fre- 
quent beauty of color and form, and their uses as gems 
and as ornamental stones, were the first inorganic objects 
to excite wonder and comment and we find many of them 
named and described in very early writings. Theophras- 
tus (3868-284 B. C.), a famous pupil of Aristotle, wrote 
a treatise ‘‘On Stones’’ in which he collected a large 
amount of information about minerals and fossils. The 
elder Pliny (23-79 A. D.), more than three centuries later, 
in his Natural History, described and named many of the 
commoner minerals. At this time it was natural fhat no 
clear distinction should be drawn between minerals and 
rocks, or even between minerals and fossils. As long as 
all study of the materials of the earth’s crust was con- 
cerned with their superficial characters, it was logical to 
include everything under the single head. There were 
some writers in the early centuries of the Christian era, 
however, who believed that fossils had been derived from 
living animals but the majority considered them to be 
only strange and unusual forms of minerals. During 
many succeeding centuries little was added to the general 
store of geological knowledge and it was not until the 
beginning of the sixteenth century, that any further 
notable progress was made. Agricola (1494-1555) was a 
physician, who, for a time, lived in the mining district of 
Joachimstal. He studied and described the minerals 
that he collected there. He was the first to give careful 
and critical descriptions of minerals, of their crystals 
and general physical properties. Unfortunately, he also 
did not realize the fundamental distinction between fos- 
sils and minerals, and probably because of his influence 
this error persisted, even until the middle of the eigh- 
teenth century. But, naturally, as the number of scien- 


Pord—Growth of Mineralogy, 1818 to 1918. 241 


tific students increased, the number of those who rejected 
this conclusion grew, until at last, the true character of 
fossils was established. The keen interest in minerals 
and fossils which was aroused by this controversy, 
together with the rapid extension of mining operations, 
drew the attention of scientific men to. other features of 
the earth’s surface and led to a more extended investi- 
gation of its characters and thus to the development of 
geology proper. It is interesting to note also that min- 
eralogy was the first of the Geological Sciences to be 
officially recognized and taught by the universities. 

Although, as has been shown, the beginnings of min- 
eralogy lie in the remote past, the science, as we know it 
to-day, can be said to have had practically its whole 
growth during the last one hundred years. Of the more 
than one thousand mineral species that may now be con- 
sidered as definitely established hardly more than two 
hundred were known in the year 1800 and these were only 
partially described or understood. It is true that Haity, 
the ‘‘father of crystallography,’’ had before this date dis- 
covered and formulated the laws of crystal symmetry, 
and had shown that rational relations existed between 
the intercepts upon the axes of the different faces of a 
erystal. It was not until 1809, however, that Wollaston 
deseribed the first form of a reflecting goniometer, and 
thus made possible the beginning of exact investigation 
of crystals. The distinctions between the different crys- 
tal groups were developed by Bernhardi, Weiss and Mohs 
between the years 1807 and 1820, while the Naumann 
system of crystal symbols was not proposed until 1826. 
The fact that doubly refracting minerals also polarize 
light was discovered by Malus in 1808, and in 1813 
Brewster first recognized the optical differences between 
uniaxial and biaxial minerals. The modern science of 
chemistry was also just beginning to develop at this 
period, enabling mineralogists to make analyses more 
and more accurately and thus by chemical means to 
establish the true character of minerals, and to properly 
classify them. 

Franz von Kobell, on page 372 of his ‘‘Geschichte der 
Mineralogie,’’ somewhat poetically describes the cond1- 
dition of the science at this period as follows: ‘‘ With the 
end of the eighteenth and the commencement of the nine- 
teenth centuries exact investigations in mineralogy first 


242 =Ford—Growth of Mineralogy, 1818 to 1918. 


began. The mineralogist was no longer content with 
approximate descriptions of minerals, but strove rather 
to separate the essential facts from those that were acci- 
dental, to discover definite laws, and to learn the rela- 
tions between the physical and chemical characters of a 
mineral. The use of mathematics gave a new aspect to 
crystallography, and the development of the optical 
relationships opened a magnificent field of wonderful 
phenomena which can be described as a garden gay with 
flowers of light, charming in themselves and interesting 
in their relations to the forces which guide and govern the 
regular structure of matter.’’ 

In the Medical Repository (vol. 2, p. 114, New York, 
1799), there occurs the following notice: ‘‘Since the pub- 
lication of the last number of the Repository an Associa- 
tion has been formed in the city of New York ‘for the 
investigation of the Mineral and Fossil bodies which com- 
pose the fabric of the Globe; and, more especially, for 
the Natural and Chemical History of the Minerals and 
Fossils of the United States,’ by the name and style 
of The American Mineralogical Society.’’ With this 
announcement is given an advertisement in which the 
society ‘‘earnestly solicits the citizens of the United 
States to communicate to them, on all mineralogical sub- 
jects, but especially on the following: 1, concerning 
stones suitable for gun flints; 2, concerning native brim- 
stone or sulphur; 3, concerning salt-petre; 4, concerning 
mines and ores of lead.’’ Further the society asks ‘‘that 
specimens of all kinds be sent to it for examination and 
determination. ’’ 

This marks apparently the beginning of the serious 
study of the science of mineralogy in the United States. 
From this time on, articles on mineralogical topics 
appeared with increasing frequency in the Medical 
Repository. Most of these were brief and were largely 
concerned with the description of the general characters 
and modes of occurrence of various minerals. Nothing 
of much moment from the scientific point of view 
appeared until many years later, but the growing inter- 
est in things mineralogical was clearly manifest. An 
important stimulus to this increasing knowledge and dis- 
cussion was furnished by Col. George Gibbs who, about 
the year 1808, brought to this country a large and notable 
mineral collection. In the Medical Repository (vol. 11, 


Ford—Growth of Mineralogy, 1818 to 1918. 243 


p. 213, 1808), is found a notice of this collection, a portion 
of which is reproduced below: 


‘*Gibbs’ grand Collection of Minerals. 


One of the most zealous cultivators of mineralogy in the 
United States is Col. G. Gibbs of Rhode Island and his taste and 
his fortune have concurred in making him the proprietor of the 
most extensive and valuable assortment of minerals that prob- 
ably exists in America. 

This rich collection consists of the cabinets possessed by the 
late Mons. Gigot D’Orcy of Paris and the Count Gregoire de 
Rozamonsky, a Russian nobleman, long resident in Switzerland. 
To which the present proprietor has added a number, either 
gathered by himself on the spot, or purchased in different parts 
of Europe . . . The whole consists of about twenty thousand 
specimens. A small part of this collection was opened to 
amateurs at Rhode Island, the last summer, and the next, if 
circumstances permit, the remainder will be exposed.’’ 


In 1802 Benjamin Silliman was appointed professor of 
chemistry and mineralogy in Yale College. After the 
Gibbs Collection was brought to America he spent much 
time with the owner in studying it and, as a result, Col. 
Gibbs offered to place the collection on exhibition in New 
Haven if suitable quarters would be furnished by the col- 
lege. This was quickly accomplished and in 1810, 1811 
and 1812 the collection was transferred to New Haven 
and arranged for exhibition by Col. Gibbs. Later, in 
1825, it was purchased by Yale and served as the nucleus 
about which the present Museum collection of the Univer- 
sity has been formed. There is no doubt but that the 
presence at this early date of this large and unusual min- 
eral collection had a great influence upon the develop- 
ment of mineralogical science at Yale, and in the country 
at large. 

In the year 1810 Dr. Archibald Bruce started the 
‘‘American Mineralogical Journal,’’ the title page of 
which reads in part as follows: ‘‘The American Mineral- 
ogical Journal, being a Collection of Facts and Observa- 
tions tending to elucidate the Mineralogy and Geology of 
the United States of America, together with other Infor- 
mation relating to Mineralogy, Geology and Chemistry, 
derived from Scientific Sources.’’ Unfortunately the 
health of Dr. Bruce failed, and the journal lasted only 
through its first volume. It had, however, ‘‘been most 
favorably received,’’ as Silliman remarks, and it was felt 


244 Ford—Growth of Mineralogy, 1818 to 1918. 


that another journal of a similar type should be insti- 
- tuted. Such a suggestion was made by Col. Gibbs to 
Professor Silliman in 1817 and this led directly to the 
founding of the American Journal of Science in 1818 
under the latter’s editorship. Although the field of the 
Journal at the very beginning was made broad and inclu- 
sive it has always published many articles on mineralog- 
ical subjects. Three of its editors-in-chief have been 
eminent mineralogists, and without question it has been 
the most important single force in the development of 
this science in the country. More than 800 well-estab- 
lished mineral species have been described since the year 
1800, of which approximately 150 have been from Amer- 
ican sources. More than two-thirds of the articles 
describing these new American minerals have first 
appeared in the pages of this Journal. While the 
description of new species is not always the most import- 
ant part of mineralogical investigation, still these fig- 
ures serve to show the large part that the Journal has 
played in the growth of American mineralogy. 

It is convenient to review the progress in Mineralogy 
according to the divisions formed by the different series, 
consisting of fifty volumes each, in which the Journal has 
been published. ‘These divisions curiously enough will 
be found to correspond closely to four quite definite 
phases through which mineralogical investigation in 
America has passed. The first series covered the years 
from 1817 to 1845. In looking through these volumes 
one finds a large number of mineralogical articles, the 
work of many contributors. The great majority of these 
papers are purely descriptive in character, frequently 
giving only general accounts of the mineral occurrences 
of particular regions. However, a number of articles 
dealing with more detailed physical and chemical descrip- 
tions of rare or new species also belong in this period. 
Among the mineralogists engaged at this time in the 
description of individual species, none was more inde- 
fatigable than Charles U. Shepard. He was graduated 
from Amherst College in 1824, at the age of twenty. In 
1827 he became assistant to Professor Silliman in New 
Haven, continuing in this position for four years. Later 
he was a lecturer in natural history at Yale, and was at 
various times connected with Amherst College and the 
South Carolina Medical College at Charleston. His 


Ford—Growth of Mineralogy, 1818 to 1918. 245 


articles on mineralogy were very numerous. He assigned 
a large number of new names to minerals, although with 
the exception of some half dozen cases, these have later 
been shown to be varieties of minerals already known and 
described, rather than new species. In spite, however, of 
his frequent hasty and inaccurate decision as to the char- 
acter of a mineral, his influence on the progress of 
mineralogy was marked. His great enthusiasm and 
ceaseless industry throughout a long life could not help 
but make a definite contribution to the science. His 
“‘Treatise on Mineralogy’’ will be spoken of in a later 
paragraph. He died in May, 1886, having published his 
last paper in the Journal in the previous September. 

The first book on mineralogy published in America was 
that by Parker Cleaveland, professor of mathematics, nat- 
ural philosophy, chemistry and mineralogy in Bowdoin 
College. The first edition was printed in 1816 and an 
exhaustive notice is given in the first volume of the Jour- 
nal (1, 35, 308, 1818); a second edition followed in 1822. 
In his preface Cleaveland gives an interesting discussion 
concerning the two opposing Huropean methods of classi- 
fying minerals. The German school, led by Werner, 
classified minerals according to their external characters 
while the French school, following Hatiy, put the empha- 
sis on the ‘‘true composition.’’ Cleaveland remarks that 
‘‘the German school seems to be most distinguished by a 
technical and minutely descriptive language; and the 
French, by the use of accurate and scientific principles in 
the classification or arrangement of minerals.’’ He, 
himself, tried to combine in a measure the two methods, 
basing the fundamental divisions upon the chemical com- 
position and using the accurate description of the physi- 
eal properties to distinguish similar species and varieties 
from each other. 

Cleaveland’s mineralogy was followed nearly twenty 
years later by the Treatise on Mineralogy by Charles 
U. Shepard already mentioned. The first part of this 
book was published in 1832. This contained chiefly an 
account of the natural history classification of minerals 
according to the general plan adopted by Mohs, the 
Austrian mineralogist. The second part of the book, 
which appeared in 1835, gave the description of indi- 
vidual species, the arrangement here being an alpha- 


246 Ford—Growth of Mineralogy, 1818 to 1918. 


betical one throughout. Subsequent editions appeared 
in 1844, 1852 and 1857. 

James Dwight Dana was graduated from Yale College 
in 1833 at the : age of twenty. Four years later (1837) he 
published “The System of Mineralogy,’’ a volume of 580 
pages. The appearance of this book was an event of 
surpassing importance in the development of the science. 
The book, of course, depended largely upon the previous 
works of Hatiy, Mohs, Naumann and other Huropean 
mineralogists, but was in no sense merely a compilation 
from them. Dana, particularly in his discussion of 
mathematical crystallography, showed much original 
thought. He also proved his originality by proposing 
and using an elaborate system of classification patterned 
after those already in use in the sciences of botany and 
zoology. He later became convinced of the undesira- 
bility of this method of classification and abandoned it 
entirely in the fourth edition of the System, published in 
1854, substituting for it the chemical classification which, 
in its essential features, is in general use to-day. The 
System of Mineralogy started in this way in 1837, has 
continued by means of successive editions to be the stand- 
ard reference book in the subject. The various editions 
appeared as follows: I, 1837; II, 1844; III, 1850; 
IV, 1854; V, 1868; VI, 1892 (by Edward S. Dana). 

J. D. Dana also contributed numerous mineralogical 
articles to the first series of volumes of the Journal. 
It is interesting to note that they are chiefly concerned 
with the more theoretical aspects of the subject, in fact 
they constitute practically the only articles of such a 
character that appeared during this period. Among the 
subjects treated were crystallographic symbols, forma- 
tion of twin crystals, pseudomorphism, origin of minerals 
in metamorphosed limestones, origin of serpentine, 
classification of minerals, ete. 

The volumes of the Second Series of the Journal cov- 
ered the vears from 1846 through 1870. This period was 
characterized by great activity in the study of the chem- 
ical composition of minerals. A number of skilled 
chemists, notably J. Lawrence Smith, George J. Brush 
and Frederick A. Genth, began about 1850 a long series 
of chemical investigations of American minerals. Very 
few articles during “this time paid much attention to the 
physical properties of the minerals under discussion, 


Ford—Growth of Mineralogy, 1818 to 1918. 247 


practically no description of optical characters was 
attempted, and only occasionally were the erystals of a 
mineral mentioned. J. D. Dana was almost the only 
writer who constantly endeavored to discover the funda- 
mental characters and relationships in minerals. He 
published many articles in these years which were con- 
cerned chiefly with the classification and grouping of 
minerals, with similarities in the crystal forms of dif- 
ferent species, with relations between chemical compo- 
sition and crystal form, chemical formulas, mineral 
nomenclature, ete. The following titles give an idea of 
the character of the more important series of articles by 
him which belong to this category: On the isomorphism 
and atomic volume of some minerals (9, 220, 1850); vari- 
ous notes and articles on homceomorphism of minerals 
(17, 85, 86, 210, 480; 18, 35, 131, 1854); on a connection 
between crystalline form and chemical constitution, with 
some inferences therefrom (44, 89, 252, 398, 1867). 

A great many new mineral names were proposed 
between 1850 and 1870, a large number of which have con- 
tinued to be well-recognized species. But there was 
also a tendency, which has not wholly disappeared even 
now, to base a mineral determination upon insufficient 
evidence, and to propose a new species with but little 
justification for it. In this connection a quotation from 
the introduction by J. D. Dana to the 3rd Supplement to 
the System of Mineralogy (4th edition) published in this 
Journal (22, page 246, 1856), will be of interest. He 
Says: 


‘‘Tt is a matter of regret, that mineral species are so often 
brought out, especially in this country, without sufficient inves- 
tigation and full description. It is not meeting the just 
demands of the science of mineralogy to say that a mineral has 
probably certain constituents, or to state the composition in a 
general way without a complete and detailed analysis, especially 
when there are no erystallographic characters to afford the 
species a good foundation. We have a right to demand that 
those who name species, should use all the means the science of 
the age admits of, to prove that the species is one that nature 
will own, for only such belong to science, and if enough of the 
material has not been found for a good description there is not 
enough to authorize the introduction of a new name in the 
science. The publication of factitious species, in whatever 
department of science, is progress not towards truth, but into 


248 Ford—Growth of Mineralogy, 1818 to 1918. 


regions of error; and often much and long labor is required 
before the science recovers from these backward steps.’’ 


J. Lawrence Smith was born in 1818 and died in 1883. 
He was a graduate of the University of Virginia and of 
the Medical College of Charleston and later spent three 
years studying in Paris. Shortly after the completion 
of his studies he went to Turkey as an advisor to the. 
government of that country in connection with the grow- 
ing of cotton there. During this time he investigated the 
_emery mines of Asia Minor, and wrote a memoir upon 
them which was later published by the French Academy. 
He served as professor of chemistry in the University of 
Virginia and later held the same chair in the University 
of Illinois. He published a long series of papers on the 
chemical composition of minerals and meteorites, as well 
as on pure chemical subjects. Among the more notable 
of his contributions are the ‘‘ Memoir on Emery’’ (1850), 
a series of papers on the ‘‘Reéxamination of American 
Minerals’? (1853) written with the collaboration of 
George J. Brush, and his ‘‘Memoir on Meteorites’’ 
(1855). 7 

George J. Brush entered on his scientific career at the 
moment when science and scientific methods of research 
were just beginning to be appreciated in this country, 
and he soon became one of the leading pioneers in the 
movement. While his half century of active service was 
largely occupied by administrative duties in connection 
with the Sheffield Scientific School, his interest in min- 
eralogy never flagged. His papers on mineralogical sub- 
jects number about thirty, all of which were published in 
this Journal. These began in 1849, even before his 
graduation from college, and continued until his last 
paper (in collaboration with 8S. L. Penfield) appeared in 
1883. Three of the early papers were written with 
J. Lawrence Smith as noted above. These papers first set 
in this country the standard for thorough and accurate 
scientific mineral investigation. Later in life he was 
active in the development of the remarkable mineral 
locality at Branchville, Conn., and, with the collaboration 
of E. S. Dana, published in this Journal (1878-90) five 
important articles on its minerals. This locality, with the 
exception of the zine deposits at Franklin Furnace, N. J., 
was the most remarkable yet discovered in this country. 
Nearly forty different mineral species were found there, 


Ford—Growth of Mineralogy, 1818 to 1918. 249 


of which nine (mostly phosphates) were new to science. 
There has certainly been no other series of descriptive 
papers on a mineralogical locality of equal importance 
published in this country. 

Jn addition to publishing original papers, Brush did 
considerable editorial work in connection with the fourth 
(1854) and fifth (1868) editions of the System of Miner- 
alogy and the Appendices to them. His Manual of 
Determinative Mineralogy, with a series of determinative 
tables adapted from similar ones by von Kobell, was first 
published in 1874. It was revised in 1878 and later 
rewritten by 8S. L. Penfield. This book did much to make 
possible the rapid and accurate determination of mineral 
species. Throughout his life, Brush was an enthusiastic 
collector of minerals, building up the notable collection 
that now bears his name. Perhaps, however, his most 
important contribution to the development of mineralogy 
in America lay rather in his influence upon his many 
students. With his enthusiasm for accurate and pains- 
taking investigation he was an inspiration to all who 
came in contact with him and his own field and science 
in general owes much to that influence. 

Among the early mineralogists in this country, who 
were concerned in the chemical analyses of minerals, 
none accomplished more or better -work than Frederick 
A. Genth. He was born in Germany in 1820 and lived 
in that country until 1848, when he came to the United 
States and settled in Philadelphia. He had studied in 
various German universities and worked under some of 
the most famous chemists of that time. His papers in 
mineralogy number more than seventy-five, in the great 
majority of which chemical analyses are given. He pub- 
lished fifty-four successive articles, the greater part of 
which appeared in this Journal, which were entitled Con- 
tributions to Mineralogy. In these he gave descriptions 
of more than two hundred different minerals, most of 
which were accompanied by analyses. He described 
more than a dozen new and well-established mineral spe- 
cies. He was especially interested in the rarer elements 
and many of his analyses were of minerals containing 
them. Especially interesting was his work with the tel- 
lurides. the species coloradoite, melonite and calaverite 
being first described by him. A long and important 
investigation was recorded on Corundum, ‘‘Its Altera- 


250 Ford—Growth of Mineralogy, 1818 to 1918. 


tions and Associate Minerals,’’ published in the Pro- 
ceedings of the American Philosophical Society in 1873 
(13, 361). Dr. Genth died in 1893. 

The period from 1860 until 1875 was not very produc- 
tive in mineralogical investigations. The first ten vol- : 
umes of the Third Series of the Journal, covering the 
years 1871-1876, contained mineralogical articles by only 
some fifteen different authors. But from that time on, 
the amount of work done and the number of investigators 
grew rapidly. With this increase in activity came also 
a decided change in the character of the work. The 
period between 1871 and 1895 can be characterized as one 
in which all the various aspects of mineral investigation 
received more nearly equal prominence. While the 
chemical composition of minerals still held rightly its 
prominent place, the investigation of the crystallographic 
and optical characters and the relationships existing 
between all three were of much more frequent occurrence. 
Kdward 8. Dana commenced his scientific work by pub- 
lishing in 1872 an article on the crystals of datolite which 
was probably the first American article concerned wholly 
with the description of the crystallography of a mineral. 
Samuel L. Penfield began his important investigations in 
1877 and the first articles by Frank W. Clarke appeared 
during this period. The first edition of the Text Book 
of Mineralogy by Edward S. Dana with its important 
chapters on Crystallography and Optical Mineralogy 
was published in 1877 and his revision of the System of 
Mineralogy (sixth edition) appeared in 1892. 

Unquestionably the foremost figure in American min- 
eralogy during this period was that of Samuel L. Pen- 
field. He embodied in an unusual degree the characters 
making for success in this science, for few investigators 
in mineralogy have shown, as he did, equal facility in all 
branches of descriptive mineralogy. He was a skilled 
chemist and possessed in a high degree that ingenuity in 
manipulation so necessary to a great analyst. He was 
also an accurate and resourceful erystallographer and 
optical mineralogist. His contributions to the science of 
mineralogy can be partially judged by the following 
brief summary of his work. He published over eighty 
mineralogical papers, practically all of which were 
printed in this Journal. These included the descriptions 
of fourteen new mineral species, the establishment of the 


Ford—Growth of Mineralogy, 1818 to 1918. 251 


chemical composition of more than twenty others, and 
the erystallization of about a dozen more. By a series 
of brilliant investigations he established the isomorphism 
between fluorine and the hydroxyl radical. He first 
enunciated the theory that the crystalline form of a min- 
eral was due to the mass effect of the acid present rather 
than that of the bases. He contributed also a number of 
articles on the stereographic projection and its use in 
crystallographic investigations, devising a series of pro- 
tractors and scales to make possible the rapid and accu- 
rate use of this projection in solving problems in 
erystallography. 

Penfield was born in 1856, was graduated from the 
Sheffield Scientific School in 1877 and immediately 
became an assistant in the chemical laboratory of that 
institution. At this time he, together with his colleague 
Horace L. Wells, made the analyses of the minerals from 
the newly discovered Branchville locality. He spent the 
years 1880 and 1881 in studying chemistry in Germany, 
returning to Yale as an instructor in mineralogy in the 
fall of 1881. Except for another semester in Kurope at 
Heidelberg he continued as instructor and professor of 
mineralogy in the Sheffield Scientific School until his 
early death in 1906. 

It is difficult to choose for mention the names of other 
investigators in Mineralogy during this period. ‘Toward 
its end a great many writers contributed to the pages of 
this Journal, more than fifty different names being 
counted for the volumes 41 to 50 of the Third Series. 
Many of these are still living and still active in scientific 
research. Mention should be made of Frank W. Clarke, 
who contributed many important articles concerning 
the chemical constitution of the silicates. His work on 
the mica and zeolite groups is especially noteworthy. 
The work of W. H. Hillebrand, particularly in regard to 
his analytical investigations of the minerals containing 
the rarer elements, was of great importance. The name 
of W. 4. Hidden should be remembered, because, with 
his keen and discriminating eye and active search for new 
mineral localities, he was able to make many additions to 
the science. 

In glancing over the indices to this Journal the close 
interrelation of mineralogy to the other sciences is strik- 
ingly shown by the fact that so many scientists whose 


252. = =Ford—Growth of Mineralogy, 1818 to 1918. 


particular fields are along other lines have published 
occasional mineralogical papers. Frequently a young 
man has commenced with mineralogical investigations 
and then later been drawn definitely into one of these 
allied subjects. Men, who have won their reputation in 
chemistry, physics, and all the various divisions of geol- 
ogy, even that of paleontology, have all contributed arti- 
cles distinctly mineralogical in character. For this 
reason the number of American writers who have pub- 
lished what may be called casual papers on mineralogy 
is very great in comparison to the number of those who 
continue such publications over a series of years. 

That the subject of meteorites is one which has been 
constantly studied by American mineralogists and petrog- 
raphers is shown by the long list of papers concerning it 
that have been published in the Journal; it should, there- 
fore, be considered briefly here. Many of these papers 
are short and of a general descriptive nature but others 
which give more fully the chemical, mineralogical and 
physical details are numerous. Among the earlier 
writers on this subject Benjamin Silliman, Jr., and C. U. 
Shepard should be mentioned. The latter was the first 
to recognize a new mineral in the Bishopville meteorite 
which he called Chladnite. The same substance ‘was 
afterwards found in a terrestial occurrence and was more 
accurately described by Kenngott under the name of 
enstatite. J. Lawrence Smith later showed that these 
two substances were identical. Smith did a large 
amount of important chemical work on meteorites.. He 
was the first to note the presence of ferrous chloride in 
meteoric iron, the mineral being afterwards named law- 
rencite in his honor. The iron-chronium sulphide, 
daubreelite, was also first described by him. Other 
names that should be mentioned in this connection are 
those of A. W. Wright who studied the gaseous con- 
stituents of meteorites, G. F. Kunz, W. E. Hidden, A. EH. 
Foote and H. A. Ward, all of whom published numerous 
descriptions of these bodies. Among the more recent 
workers in this field the names of G. P. Merrill and O. C. 
Farrington deserve especial mention. 

The publication of the Fourth Series of the Journal 
began in 1896. Although the years since then have seen 
a great amount of very important work accomplished, the 
history of the period is fresh in the minds of all and as 


Ford—Growth of Mineralogy, 1818 to 1918. 253 


the majority of the active workers are still living and 
productive it seems hardly necessary to go into great 
detail concerning it. Twenty years ago it seemed to 
some mineralogists that the science could almost be con- 
sidered complete. All the commoner minerals had cer- 
tainly been discovered and exhaustively studied. Little 
apparently was left that could be added to our knowledge 
of them. New occurrences would still be recorded, new 
erystal habits would be observed, and an occasional new 
and small crystal face might be listed, but few facts of 
ereat importance seemed undiscovered. This view was 
not wholly justified because new facts of interest and 
importance have continuously been brought forward, and 
the finding of new minerals does not appear to diminish 
in amount with the years. The work of the investigators 
on the United States Geological Survey along these lines 
is especially noteworthy. 

This last of our periods, however, is chiefly signalized 
by a practically new development along the lines that 
might be characterized as experimental mineralogy. 
New ways have been discovered in which to study min- 
erals. The important but hitherto baffling problems of 
their genesis, together with their relations to their 
surroundings, and to associated minerals, have been 
attacked by novel methods. 

In this pioneer work that of the Geophysical Labora- 
tory of the Carnegie Institution of Washington has been 
of the greatest importance. This laboratory was estab- 
lished in 1905 and, under the directorship of Arthur L. 
Day, a notable corps of investigators has been assembled 
and remarkable work already accomplished. While the 
field of investigation of the laboratory is broader than 
that of mineralogy, including much that belongs to 
petrography, vuleanology, ete., still the greater part of 
the work done can be properly classed as mineralogical in 
character and should be considered here. Because of its 
ereat value, however, it was felt that an authoritative, 
although necessarily, under existing conditions, a brief, 
account of it should be given. A concise summary of the 
objects, methods and results of the investigations of the 
laboratory has been kindly prepared by a member of its 
staff, Dr. R. B. Sosman, and is given later. 

During the last few years another line of investigation 
has been opened by the discovery of the effect of crystal- 


254 Ford—Growth of Mineralogy, 1818 to 1918. 


line structure upon X-rays. Through the refraction or 
reflection of the X-ray by means of the ordered arrange- 
ment of the particles forming the crystalline network, we 
are apparently going to be able to discover much con- 
cerning the internal structure of crystals. And, partly 
through these discoveries, is likely to come in turn the 
solution of the hitherto insolvable mystery of the consti- 
tution of matter. Without doubt the multitudinous facts 
of mineralogy assembled during the past century by the 
painstaking investigation of a large number of scientists 
are destined to play a large part in the solution of this 
problem. Further, it does not seem too bold a prophecy 
to suggest, that the time will come when it will be possi- 
ble to assemble all these unorganized facts that we know 
about minerals into a harmonious whole and that we shall 
be then able to formulate the underlying and fundamental 
principles upon which they all depend. These are the 
great problems for the future of mineralogical inves- 
tigation. 


Sosman—W ork of the Geophysical Laboratory. 255 


Arr. VIII A.—The Work of the Geophysical Laboratory 
of the Carnegie Institution of Washington; by R. B. 
SosMAN. 


There are three methods of approach to the great 
problem of rock formation. The first undertakes to 
reproduce by suitable laboratory experiments some of 
the observed changes in natural rocks. The second seeks 
to apply the principles of physical chemistry to a great 
body of carefully gathered statistics. The third method 
of attack is like the first in being a laboratory method, 
and like the second in seeking to apply existing knowl- 
edge to the association of minerals as found in rocks, but 
in its procedure differs widely from both. It consists of 
bringing together pure materials under measurable con- 
ditions, and thus in establishing by strictly quantitative 
methods the relations in which minerals can exist 
together under the conditions of temperature and pres- 
sure that have the power to affect such relations. 

Jt is to this third method of investigation of the prob- 
lems of the rocks that the Geophysical Laboratory has 
been devoted since its establishment in 1905. It has 
proved entirely practicable to make quantitative studies 
of the relations among the principal earth-forming 
oxides (silica, alumina, magnesia, lime, soda, potash, and 
the oxides of iron) over a very wide range of tempera- 
tures. The resources of physics have proved adequate 
to establish temperature with a high degree of precision 
and to measure the quantity of energy involved in the 
various reactions. The chemist ‘has been able to obtain 
materials in a high degree of purity, and to follow out in 
detail the chemical relationships that exist among the 
earth-forming oxides. The petrographic laboratory has 
been available for the comparison of synthetic laboratory 
products with the corresponding natural minerals. 

It has also proved entirely practicable to extend the 
same methods of research to some of the principal ore 
minerals such as the sulphides of copper. Other infor- 
mation which is certain to be of ultimate economic value 
has also come out of the thorough study of the silicates, 
which are basic materials for the vast variety of indus- 
tries which are classed under the name of ceramic indus- 


256 Sosman—Work of the Geophysical Laboratory. 


tries. The best example of this is the facility with which 
the experience and the personnel of the laboratory has 
been adapted to the very important problem of manufac- 
turing an adequate supply of optical glass for the needs 
of the United States in the present war. 

It has further been possible to show within the last two 
years that rock formation in which volatile ingredients 
play a necessary and determining part can be completely 
studied in the laboratory with as much precision as 
though all the components were solids or liquids. 

Along with the laboratory work on the formation of 
minerals and rocks has gone an increasing amount of field 
work on the activities of accessible voleanoes, such as 
Kilauea and Vesuvius, where the fusion and recrystal- 
lization of rocks on a large scale can be observed and 
studied. 

There was once a time when the confidence of the lab- 
oratory in the capacity of physics and chemistry to solve 
geological problems was not shared by all geologists. 
There were some who were inclined to view with consid- 
erable apprehension the vast ramifications and com- 
plications of natural rock formation as a problem 
impossible of adequate solution in the laboratory. It is, 
therefore, a matter of satisfaction to all those who have 
participated in these efforts to see the evidences of this 
apprehension disappearing gradually as the work has 
progressed. A careful appraisement of the situation 
to-day, after ten years of activity, reveals the fact that 
the tangible grounds for anxiety about the accessibility 
of the problems which were confronted at first are now 
for the most part dissipated. 

It will not be possible to review in detail the lines of 
work sketched above. An outline of the synthetic work 
on systems of the mineral oxides and a paragraph on the 
voleano researches will perhaps suffice to indicate the 
general plan and purpose of the laboratory’s work. It 
should be added that the results of many of the researches 
of the laboratory, detailed below, have been published in 
the pages of this Journal (see 21, 89, 1906, and later 
volumes). 

Mineral Researches.—The mineral studies include: 

I. One-component systems: silica, with its numerous 
polymorphic forms and their relations to temperature 


Sosman—W ork of the Geophysical Laboratory. 257 


and the conditions of rock formation; alumina; mag- 
nesia; and lime. 

Il. Two-component systems: silica-alumina, includ- 
ing sillimanite and related minerals; silica-magnesia, 
including the tetramorphic metasilicate MgSiO,; silica- 
hme, including wollastonite; the alkali silicates, par- 
ticularly with reference to their equilibria with carbon 
dioxide and with water; ferric oxide-lime; alumina-lime; 
alumina-magnesia, including spinel; and hematite-mag- 
netite, a solid-solution series of an unusual type. 

Ill. Three-component systems: silica-alumina-mag- 
nesia, completed but not yet published; silica-alumina- 
lime, complete, including the compounds that enter into 
the composition of portland cement; silica-magnesia- 
lime, completed but not yet published, including. however, 
published work on the diopside-forsterite-silica system, 
and on the CaSiO,-MgSiO, series; and alumina-mag- 
nesia-lime. 

IV. Four components: SiO,-Al,O,-—MgO-CaO: the in- 
complete system anorthite-forsterite-silica; Si0,-Al,O,- 
CaO-Na,O: the series of lime-soda feldspars (albite- 
anorthite), and the series nephelite (carnegieite)-anor- 
thite; Si0,-Al,0,-Na,O-K,O: the sodium-potassium 
nephelites. 

V. Five components: Si0O,-Al,0,-MgO-CaO-Na,O: 
the ternary system diopside-anorthite-albite (haplo-basal- 
tic and haplo-dioritic magmas). 

Fairly complete studies have also been made of the 
mineral sulphides of iron, copper, zinc, cadmium, and 
mercury, and the conditions controlling the secondary 
enrichment of copper sulphide ores are now being inves- 
tigated. In connection with the sulphide investigations, 
the hydrated oxides of iron have been studied chemically 
and microscopically and the results will soon be ready for 
publication. , 

Throughout the work the mere accumulation of bodies 
of facts has been held to be secondary in importance to 
the development of new methods of attack and the eval- 
uation of new general principles, and the specific prob- 
lems studied have been selected from this point of view. 

Volcano Researches.—A branch of the laboratory’s 
work that is of general as well as petrological interest 
is the study of active voleanoes. Observations and col- 
lections have been made at Kilauea, Vesuvius, Etna, 


Am. Jour. Sct.—Fourts Series, Vout. XLVI, No. 271.—Juty, 1918. 
9 


258 Sosman—W ork of the Geophysical Laboratory. 


Stromboli, Vulcano, and (through the courtesy of the 
directors of the National Geographic Society) Katmai in 
Alaska. The great importance of gases in voleanicity is 
emphasized by all the studies. The active gases include 
hydrogen and water vapor, carbon monoxide and carbon 
dioxide, and sulphur and its oxides, as well as a variety 
of other compounds of lesser importance. The crater of 
Kilauea proves to be an active natural gas-furnace, in 
which reactions are continuously occurring among the 
gases, often resulting in making the lava basin hotter at 
the surface than it is at some depth. These reactions 
are being studied in the laboratory on mixtures of the 
pure constituent gases in known proportions, in order to 
lay the foundation for accurate interpretation and pre- 
diction concerning the gases as actually collected from 
the voleanoes themselves. 


Wells & Foote—One Hundred Years of Chemistry. 259 


Art. [IX.—The Progress of Chemistry during the past 
One Hundred Years; by Horace L. Wexts and Harry 
W. Foote. 


INTRODUCTION. 


As we look back to the time of the founding of the 
Journal in 1818, we see that the science of chemistry had 
recently made and was then making great advances. 
That the scientific men of those days were much 
impressed with what was being accomplished is well 
shown by the following statement made in an early num- 
ber of the Journal (3, 330, 1821) by its founder in 
reviewing Gorham’s Elements of Chemical Science. He 
says: ‘‘The present period is distinguished by wonderful 
mental activity; it might indeed be denominated as the 
intellectual age of the world. At no former period has 
the mind of man been directed at one time to so many and 
so useful researches.”’ 

A very remarkable revolution in chemical ideas had 
recently taken place. Soon after the discovery of oxy- 
gen by Priestley in 1774, and the subsequent discovery 
by Cavendish that water was formed by the combustion 
of hydrogen and oxygen, Lavoisier had explained com- 
bustion in general as oxidation, thus overthrowing the 
curious old phlogiston theory which had prevailed as the 
basis of chemical philosophy for nearly a century. 

The era of modern chemistry had thus begun, and the 
additional views that matter was indestructible and that 
chemical compounds were of constant composition had 
been generally accepted at the beginning of the nine- 
teenth century. 

Dalton had announced his atomic theory in 1802, hav- 
ing based it largely upon the law of multiple proportions 
which he had previously discovered, and he had begun 
to express the formulas for compounds in terms of 
atomic symbols. 

In 1808 Gay-Lussac had discovered his law of gas com- 
bination in simple proportions,! a law of supreme import- 
ance in connection with the atomic theory, but neither he 
nor Dalton had seen this theoretical connection. Avo- 


*It appears that the most accurate experimental demonstration ever made 
of this law was that of E. W. Morley, published in the Journal (41, 220, 
276, 1891). He showed that 2-0002 volumes of hydrogen combine with one 
volume of oxygen. 


260 Wells & Foote—One Hundred Years of Chemistry. 


gadro had understood it, however, and in 1811 had 
reached the momentous conclusion that all gases and 
vapors have equal numbers of molecules in equal volumes 
at the same temperature and pressure. 

Davy in 1807 had isolated the alkali-metals, sodium 
and potassium, by means of electrolysis, thus practically 
dispelling the view that certain earthy substances might 
be elementary; and about four years later he had demon- 
strated that chlorine was an element, not an oxide as had 
been supposed previously, thus overthrowing Lavoisier’s 
view that oxygen was the characteristic constituent of all 
acids. 

At the time that our period of history begins, the 
atomic theory had been accepted generally, but in a some- 
what indefinite form, since little attention had been paid 
to Avogadro’s principle, and since Dalton had used only 
the principle of greatest simplicity in writing the formu- 
las of compounds, considering water as HO and ammonia 
NH, for example. At this time, however, Berzelius for 
ten or fifteen years had been devoting tremendous energy 
to the task of determining the atomic weights of nearly 
all of the elements then known by analyzing their 
compounds. He had confirmed the law of multiple pro- 
portions, accepted the atomic theory, and utilized Avo- 
gadro’s principle, and it is an interesting coincidence 
that his first table of atomic weights was published in the 
year 1818. 

An interesting account of the views on chemistry held 
at about that time was published in the Journal by Deni- 
son’ Olmsted (11, °349, 1826; -12, 1. 1620), sito 
recently become professor of natural philosophy in Yale 
College. 

The most illustrious European chemists of that time 
were Berzelius of Sweden, Davy of England, and Gay- 
Lussac of France, and the curious circumstance may be 
mentioned that all three of them and also Benjamin Silli- 
man, the founder of the Journal, were born within a 
period of eight months in 1778-1779. 

In this country Robert Hare of Philadelphia and Ben- 
jamin Silliman were undoubtedly the most prominent 
chemists of those days. Hare is best known for his 
invention of the compound blowpipe, but his contribu- 
tions to the Journal were very numerous, beginning 
almost with the first volume and continuing for over 


Wells € Foote—One Hundred Years of Chemistry. 261 


thirty years. Among the first of these contributions was 
a most vigorous but well-merited attack upon a Doctor 
Clark of Cambridge, England, who had copied his inven- 
tion without giving him proper credit. He begins (2, 
281, 1820) by saying: ‘‘Dr. Clark has published a book 
on the gas blowpipe in which he professes a sincere desire 
to render everyone his due. That it would be difficult for 
the conduct of any author to be more discordant with 
these professions, I pledge myself to prove in the fol- 
lowing pages.”’ 

Hare also invented a galvanic battery which he called 
a ‘‘deflagrator,’’ consisting of a large number of single 
cells in series. With this, using carbon electrodes, he 
was able to obtain a higher temperature than with his 
oxy-hydrogen blowpipe. He was the first to apply gal- 
vanic ignition to blasting (21, 139, 1832), and he first 
earried out electrolyses with the use of mercury as the 
cathode (37, 267, 1839). In this way he prepared 
metallic calcium and other metals from solutions of their 
chlorides, while the principle employed by him has in 
recent times been used as the basis of a very important 
process for manufacturing caustic potash and soda. 

Silliman, who had become an intimate friend of Hare 
during two periods of chemical study under Woodhouse 
in Philadelphia in 1802-1804, and who soon afterwards 
spent fourteen months as a student abroad, chiefly in 
England and Scotland, took a broad interest in science 
and gave much attention to geology as well as to chem- 
istry. In spite of this divided interest and his work as 
a teacher, popular scientific lecturer, and editor, he found 
time for a surprising amount of original chemical work. 
For instance, using Hare’s deflagrator, he showed that 
carbon was volatilized in the electric are (5, 108, 1822) ; 
he was the first in this country to prepare hydrofluoric 
acid (6, 354, 1823), and he first detected bromine in one of 
our natural brines (18, 142, 1830). 


: ATOMIC WEIGHTS. 


As soon as the atomic theory was accepted, the relative 
weights of the atoms became a matter of vital importance 
in connection with formulas and chemical calculations. 
In advancing his theory, Dalton had made some very 
rough atomic weight determinations, and it has been men- 
tioned already that Berzelius, at the time that our histor- 


262 Wells & Foote—One Hundred Years of Chemistry. 


ical period begins, was engaged in the prodigious task of 
accurately determining these constants for nearly all the 
known elements. It is recorded that he analyzed quan- 
titatively no less than two thousand compounds in 
connection with this work during his career. His table 
of 1818 has proved to be remarkably accurate for that 
pioneer period, and it indicates his remarkable skill as an 
analyst. 

It is to be observed that Berzelius in this early table 
made use of Avogadro’s principle in connection with 
elements forming gaseous compounds, and thus obtained 
correct formulas and atomic weights in such cases, but 
that in many instances his atomic weights and those now 
accepted bear the relation of simple multiples to one 
another, because he had then no means of deciding upon 
the formulas of many compounds except the rule of 
assumed simplicity. For example, the two oxides of 
iron now considered to be FeO and Fe,O, he regarded as 
FeO, and FeQO,, knowing as he did that the ratio of 
oxygen in them was 2 to 3, and believing that a single 
atom of iron in each was the simplest view of the case, 
so that as the consequence of these formulas the atomic 
weight of iron was then considered to be practically 
twice as great in its relation to oxygen as at present. 

These old atomic weights of Berzelius, used with the 
corresponding formulas, were just as serviceable for cal- 
culating compositions and analytical factors as though 
the correct multiples had been selected. As time went 
on, the true multiples were gradually found from consid- 
erations of atomic heats, isomorphism, vapor densities, 
the periodic law, and so on, and suitable changes were 
made in the chemical formulas. 

Berzelius used 100 parts of oxygen as the basis of his 
atomic weights, a practice which was generally followed 
for several decades. Dalton, however, had originally 
used hydrogen as unity as the basis, and this plan finally 
came into use everywhere, as it seemed to be more log- 
ical and convenient, because hydrogen has the smallest 
atomic weight, and also because the atomic weights of a 
number of common elements appeared to be exact multi- 
ples of that of hydrogen, thus giving simpler numbers for 
use in calculations. 7 

Within a few years a slight change has been made by 


Wells € Foote—One Hundred Years of Chemistry. 263 


the adoption of oxygen as exactly 16 as the basis, which 
gives hydrogen the value of 1-008. 

As early as 1815, Prout, an English physician, had 
advanced the view that hydrogen is the primordial sub- 
stance of all the elements, and consequently that the 
atomic weights are all exact multiples of that of hydro- 
gen. This hypothesis has been one of the incentives to 
investigations upon atomic weights, for it has been found 
that these constants in the cases of a considerable num- 
ber of the elements are very close to whole numbers 
when based upon hydrogen as unity, or even still closer 
when based upon oxygen as 16. 

With our present knowledge Prout’s hypothesis may 
be regarded as disproved for nearly all the elements 
whose atomic weights have been accurately determined, | 
but the close or even exact agreement with it in a few 
cases is still worthy of consideration. There is an inter- 
esting letter from Berzelius to B. Silliman, Jr., in the 
Journal (48, 369, 1845) in which Berzelius considers the 
theory entirely disproved. 

For a long time entire reliance was placed upon the 
atomic weights obtained by Berzelius, but it came to be 
observed that the calculation of carbon from carbon diox- 
ide appeared to give high results in certain cases, so that 
doubt arose as to the accuracy of Berzelius’s work. Con- 
sequently in 1840 Dumas, assisted by his pupil Stas, made 
a new determination of the atomic weight of carbon, and 
found that the number obtained by Berzelius, 12-12, was 
shghtly too large. Subsequently Dumas determined 
more than twenty other atomic weights, but this great 
amount of work did not bring about any considerable 
improvement, for it appears that Dumas did not greatly 
excel Berzelius in accuracy, and that the latter had made 
one of his most noticeable errors in connection with 
carbon. 

Soon after assisting Dumas in the work upon carbon, 
Stas began his very extensive and accurate, independent 
determinations, leading to the publication of a book in 
1867 describing his work. Stas made many improve- 
ments in methods by the use of great care in purifying 
the substances employed, and especially by using large 
quantities of material in his determinations, thus dimin- 
ishing the proportional errors in weighing. His results, 


264 Wells € Foote—One Hundred Years of Chemistry. 


which dealt with most of the common elements, were 
accepted with much confidence by chemists everywhere. 

Stas reached the conclusion that there could be no real 
foundation for Prout’s hypothesis, since so many of his 
atomic weights varied from whole numbers, and this 
opinion has been generally accepted. 

The first accurate atomic weight determination pub- 
lished in the Journal was that by Mallett on lithium (22, 
349, 1856; 28, 349, 1859), showing a result almost identi- 
cal with that accepted at the present time. Johnson and 
Allen’s determination (35, 94, 1863) on the rare element 
cesium was carried out with extraordinary accuracy. 
Lee, working with Wolcott Gibbs, made good determina- 
tions on nickel and cobalt (2, 44, 1871). The work of 
Cooke on antimony (15, 41, 107, 1878) was excellent. 

Concerning the more recent work published elsewhere 
than in the Journal, attention should be called particu- 
larly to the investigations that have been carried on for 
the past twenty-five years by Richards and his associates 
at Harvard University. Richards has shown masterly 
ability in the selection of methods and in avoiding errors. 
His results have displayed such marvelous agreements 
among repeated determinations by the same and by dif- 
ferent processes as to inspire the greatest confidence. 
His work has been very extensive, and it is a great credit 
to our country that this atomic weight work, so superior 
to all that has been previously done, is being carried 
out here. 

It may be mentioned that for a number of years the 
decision in regard to the atomic weights to be accepted 
has been in the hands of an International Committee of 
which our fellow countryman F. W. Clarke has been 
chairman. In connection with this position and pre- 
viously, Clarke has done valuable service in re-calculat- 
ing and summarizing atomic weight determinations. 


ANALYTICAL CHEMISTRY. 


Analysis is of such fundamental importance in nearly 
every other branch of chemical investigation that its 
development has been of the utmost importance in con- 
nection with the advancement of the science. It attained, 
therefore, a comparatively early development, and one 
hundred years ago it was in a flourishing condition, par- 
ticularly as far as inorganic qualitative and oravimetric 


Wells & Foote—One Hundred Years of Chemistry. 265 


analysis were concerned. There is no doubt that Ber- 
zelius, whose atomic weight determinations have already 
been mentioned, surpassed all other analysts of that time 
in the amount, variety, and accuracy of his gravimetric 
work. He lived through three decades of our period, 
until 1848. 

During the past century there has been constant prog- 
ress in inorganic analysis, due to improved methods, 
better apparatus and accumulated experience. An 
excellent work on this subject was published by H. Rose, 
a pupil of Berzelius, and the methods of the latter, with 
many improvements and additions by the author and 
others, were thus made accessible. Fresenius, who was 
born in 1818, did much service in establishing a labora- 
tory in which the teaching of analytical chemistry was 
made a specialty, in writing text-books on the subject 
and in establishing in 1862 the ‘‘Zeitschrift fur analy- 
tische Chemie,’’ which has continued up to the present 
time. 

Besides Berzelius, who was the first to show that min- 
erals were definite chemical compounds, there have been 
many prominent mineral analysts in Europe, among 
whom Rammelsberg and Bunsen may be mentioned, but 
there came a time towards the end of the nineteenth cen- 
tury when the attention of chemists, particularly in Ger- 
many, was so much absorbed by organic chemistry that 
mineral analysis came near becoming a lost art there. 
It was during that period that an English mineralogist, 
visiting New Haven and praising the mineral analyses 
that were being carried out at Yale, expressed regret that 
there appeared to be no one in England, or in Germany 
either, who could analyze minerals. 

The best analytical work done in this country in the 
early part of our period was chiefly in connection with 
mineral analysis, and a large share of it was published in 
the Journal. Henry Seybert, of Philadelphia, in par- 
ticular, showed remarkable skill in this direction, and 
published numerous analyses of silicates and other min- 
erals, beginning in 1822. It was he who first detected 
boric acid in tourmaline (6, 155, 1822), and beryllium in 
chrysoberyl (8, 105, 1824). His methods for silicate 
analyses were very similar to those used at the present 
time. 

J. Lawrence Smith in 1853 described his method for 


266 Wells é Foote—One Hundred Years of Chemistry. 


determining alkalies in minerals (16, 53), a method which 
in its final form (1, 269, 1871) is the best ever devised for 
the purpose. He also described (15, 94, 1853) a very 
useful method, still largely used in analytical work, for 
destroying ammonium salts by means of aqua regia. 
Carey Lea (42, 109, 1866) described the well-known test 
for iodides by means of potassium dichromate. F. W. 
Clarke (49, 48, 1870) showed that antimony and arsenic 
could be quantitatively separated from tin by the pre- 
cipitation of the sulphides in the presence of oxalic acid. 
In 1864 Wolcott Gibbs (37, 346) began an important 
series of analytical notes from the Lawrence Scientific 
School, and he worked out later many difficult analytical 
problems, particularly in connection with his extensive 
researches upon the complex inorganic acids. 

From 1850 on, Brush and his students made many 
important investigations upon minerals, and from 1877 
Penfield (13, 425), beginning with an analysis of a new 
mineral from Branchville, Connecticut, described by 
Brush and HK. 8. Dana, displayed remarkable skill and 
industry in this kind of work. Both of the writers of 
this article were fortunate in being associated with Pen- 
field in some of his researches upon minerals and one of 
us began as he did with the Branchville work. It is 
probably fair to say that Penfield did the most accurate 
work in mineral analysis that has ever been accom- 
plished, and that he was similarly successful in erystal- 
lography and other physical branches of mineralogy. 

The American analytical investigations that have been 
mentioned were all published in the Journal, with the 
exception of a part of Gibbs’s work. Many other Amer- 
ican workers at mineral analysis might be alluded to 
here, but only the excellent work of a number of chemists 
in the United States Geological Survey will be mentioned. 
Among these Hillebrand deserves particular praise for 
the extent of his investigations and for his careful 
researches in improving the methods of rock analysis. 

To our own Professor Gooch especial praise must be 
accorded for the very large number of analytical methods 
that have been devised, or critically studied, by him and 
his students, and for the excellent quality of this work. 
The publications in the Journal from his laboratory 
began in 1890 (39, 188), and the extraordinary extent of 
this work is shown by the fact that the three hundredth 


Wells € Foote—One Hundred Years of Chemistry. 267 


paper from the Kent Laboratory appeared in May, 1918. 
These very numerous and important investigations have 
been of great scientific and practical value, and they have 
formed a striking feature of the Journal for nearly 30 
years. In 1912 Gooch published his ‘‘Methods in Chem- 
ical Analysis,’’ a book of over 500 pages, in which the 
work in the Kent Chemical Laboratory up to that time 
was concisely presented. Among the many workers who 
have assisted in these investigations, P. E. Browning, W. 
A. Drushel, F'. S. Havens, D. A. Kreider, C. A. Peters, I. 
K. Phelps and R. G. Van Name are particularly promi- 
nent. Besides many other useful pieces of apparatus, 
the perforated filtering crucible was devised by Gooch, 
and this has brought his name into everyday use in all 
chemical laboratories. 

Volumetric analysis was originated by Gay-Lussac, 
who described a method for chlorimetry in 1824, for 
alkalimetry in 1828, and for the determination of silver 
and chlorides in 1832. Margueritte devised titrations 
with potassium permanganate in 1846, while Bunsen, not 
far from the same time, introduced the use of iodine and 
sulphur dioxide solutions for the purpose of determining 
many oxidations and reductions. We owe to Mohr some 
improvements in apparatus and a German text-book on 
the subject, while Sutton wrote an excellent English work 
on volumetric analysis, of which many editions have 
appeared. 

While volumetric analysis began to be used less than 
one hundred years ago, its applications have been grad- 
ually extended to a very great degree, and it is not only 
exceedingly important in investigations in pure chemis- 
try, but its use is especially extensive in technical labora- 
tories where large numbers of rapid analyses are 
required. 

Not a few volumetric methods have been devised or 
improved in the United States, but mention will be made 
here only of Cooke’s important method for the deter- 
mination of ferrous iron in insoluble silicates, published 
in the Journal (44, 347, 1867); to Penfield’s method for 
the determination of fluorine in 1878; and to the more 
recent general method of titration with an iodate in 
strong hydrochloric acid solutions, due to L. W. 
Andrews, a number of applications of which have been 
worked out in the Sheffield Laboratory. 


268 Wells &é Foote—One Hundred Years of Chemistry. 


A considerable amount of work with gases had been 
done by Priestley, Scheele, Cavendish, Lavoisier, Dalton, 
Gay-Lussac, and others before our hundred-year period 
began. Cavendish, about 1780, had analyzed atmos- 
pheric air with remarkable accuracy, and had even sep- 
arated the argon from it and wondered what it was, and 
later Gay-Lussac had shown great skill in the study of 
gas reactions. During our period gas analysis has been 
further developed by many chemists. Bunsen, in par- 
ticular, brought the art to a high degree of perfection in 
the course of a long period beginning about 1838, the last 
edition of his ‘‘Methods of Gas Analysis’’ having been 
published in 1877. ) 

Important devices for the simplification of gas-analy- 
sis in order that it might be used more conveniently for 
technical purposes have been introduced by Orsat in 
France and by Winkler, Hempel and Bunte in Germany. 

It appears that our countryman Morley has surpassed 
all others in accurate work with gases in connection 
with his determinations of the combining weights and 
volumes of hydrogen and oxygen about the year 1891. 
Some of his publications have appeared in the Journal 
(30, 140, 1885; 41, 220, 1891; and others). 

Electrolytic analysis, involving the deposition of 
metals, or sometimes of oxides, usually upon a platinum 
electrode, was brought into use in 1865 by Wolcott Gibbs 
through an article published in the Journal (39, 58, 1865). 
He there described the electrolytic precipitation of cop- 
per and of nickel by the methods still in use. The appli- 
cation of the process has been extended to a number of 
other metals, and it has been largely employed, particu- 
larly in technical analyses. Important. investigations 
and excellent books on this subject have been the contri- 
butions of Edgar F. Smith of the University of Pennsyl- 
vania, and the useful improvement, the rotating cathode, 
was devised by Gooch and described in the Journal (15, 
320, 1903). 


GENERAL INORGANIC CHEMISTRY. 


The Chemical Symbols.—It is to Berzelius that we owe 
our symbols for the atoms, derived usually from their 
Latin names, such as C for carbon, Na for sodium, Cl for 
chlorine, Fe for iron. Ag for silver, and Au for gold. 
We owe to him also the use of small figures to show the 


Wells & Foote—One Hundred Years of Chemistry. 269 


number of atoms in a formula, as in N,O,;. This was a 
marked improvement over the hieroglyphic symbols pro- 
posed by Dalton, which were set down as many times as 
the atoms were supposed to occur in formulas, forming 
groups of curious appearance, but in some respects not 
unlike some of our modern developed formulas. The 
advantages of Berzelius’s symbols were their simplicity, 
legibility, and the fact that they could be printed without 
the need of special type. It is true that at a later period 
Berzelius used certain symbols with horizontal lines 
crossing them to represent double atoms, and that these 
made some difficulty in printing. It should be mentioned 
also that Berzelius at one time made an effort to simplify 
formulas by placing dots over other symbols to represent 
oxygen, and commas to represent sulphur atoms. Hixam- 
ples of these are: 


Cas, calcium sulphate ; Fe, iron disulphide 


This form of notation was quite extensively employed 
for a time, especially by mineralogists, but it was entirely 
abandoned later. 

It is interesting to notice that Dalton, who lived mata 
1844, to reach the age of 78, differed from other chemists 
in refusing to accept the letter-symbols of Berzelius. 
In a letter written to Graham in 1837 he said: ‘‘Ber- 
zelius’s symbols are horrifying. A young student in 
chemistry might as soon learn Hebrew as to make him- 
self acquainted with them. They appear like a chaos of 
atoms ... and to equally perplex the adepts of science, 
to discourage the learner, as well as to cloud the beauty 
and simplicity of the atomic theory.’’ 

This forcibly expressed opinion was apparently tinged 
with self-esteem, but there is no doubt that Dalton was 
sincere in believing that the atoms were best represented 
by his circular symbols, because, as is well known, he 
thought that all the atoms were spherical in form, and it 
is evident that circles give the proper picture of spherical 
objects. At the present time some insight as to the 
structure of atoms is being gained, and it appears possi- 
ble that the time may come when pictures of their 
external appearance that are not wholly imaginary may 
be made. 


270 Wells & Foote—One Hundred Years of Chemistry. 


Changes in Formulas——Hven before the year 1826, 
Berzelius displayed great skill in arriving at many for- 
mulas that agree with our present ones, for example, H,O 
for water, ZnCl, for zine chloride, N.O, for nitric acid 
(anhydride), CaO for calcium oxide, CO and CO, for the 
oxides of carbon, and many others. But at the same 
period other authorities, especially Gay-Lussac in France 
and Gmelin in Germany, on account of a lack of appreci- 
ation for Avogadro’s principle and for other reasons, 
such as the use of symbols to represent combining 
weights rather than atoms, were using different formulas 
for some of these compounds, such as HO, ZnCl and NO,, 
so that their formulas for many of the compounds of 
hydrogen, chlorine, nitrogen and several other elements 
differed from those of Berzelius. The employment of 
different formulas involved the use of different atomic 
or combining weights. For example, with the formula 
H,O for water the composition by weight requires the 
ratio 1 to 16 for the weights of the hydrogen and oxy- 
gen atoms, while with HO the ratio is 1 to 8. 

Berzelius attempted to bring about greater uniformity 
in formulas and atomic weights by making changes in his 
table of atomic weights published in 1826. He prac- 
tically donbled the relative atomic weights of hydrogen, 
chlorine, nitrogen, and of the other elements that gave 
twice as many atoms in his formulas as in those of others, 
and at the same time he wrote the symbols of these 
elements with a bar across them to indicate that they 
represented double atoms. For example, he wrote: 


HO Zn€l NO, 


instead of 
HO, ZnCl, N,O, 


This appears to have been an unfortunate concession 
to the views of others on the part of Berzelius, for the 
barred symbols were not generally adopted, partly on 
account of difficulties in printing, and the great achieve- 
ment in theory made by him was lost sight of for a long 
period of time. | 

‘The Law of Atomic Heats. —In 1819, Dulong and Petit 
of France, from experiments upon the ' specific heats of a 
number of solid elementary substances, came to the con- 
clusion that the atoms of simple substances have equal 
capacities for heat, or in other words, that the specific 


Wells & Foote—One Hundred Years of Chemistry. 271 


heats of elements multiplied by their atomic weights give 
a constant called the atomic heat. For instance, the 
specific heats of sulphur, iron, and gold have been given 
as 0-2026, 0-110, and 0-0324, while their atomic weights 
are about 32, 56, and 197, respectively; hence the atomic 
heats obtained by multiplication are 6-483, 6-116, and 
6-383. 

Further investigations showed that the atomic heats 
display a considerable variation. Those of carbon, 
boron, beryllium, and silicon are very low at ordinary 
temperatures. although they increase and approach the 
usual values at higher temperatures. More recent work 
has shown, however, that the specific heats of other ele- 
ments vary greatly with the temperature, almost disap- 
pearing at the temperature of liquid hydrogen, and hence 
possibly disappearing entirely at the absolute zero, where 
the electrical resistance of the metals appears to vanish 
hkewise. ; 

It has been found that most of the solid elements near 
ordinary temperatures give atomic heats that are 
approximately 6-4. Berzelius applied the law in fixing 
a number of atomic weights, and its importance for this 
purpose is still recognized. 

It may be mentioned here that two well-known Yale 
men, W. G. Mixter and EK. S. Dana, while students in 
Bunsen’s laboratory at Heidelberg in 1873, made deter- 
minations of the specific heats of boron, silicon, and zir- 
conium. This was the first determination of this con- 
stant for zirconium, and it was consequently important 
in establishing the atomic weight of that element. 

Isomorphism and Polymorphism.—Mitscherlich ob- 
served in 1818 that certain phosphates and arsenates 
have the same crystalline form, and afterwards he 
reached the conclusion that identity in form indicates 
similarity in composition in connection with the number 
of atoms and their arrangement. This law of isomorph- 
ism was of much assistance in the establishment of cor- 
rect formulas and consequently of atomic weights. For 
instance, since the carbonates of barium, strontium, and 
lead erystallize in the same form, the oxides of these 
metals must have analogous formulas. From such con- 
siderations Berzelius was able to make several improve- 
ments in his atomic weight table of 1826. 

Mitscherlich was the first to observe two forms of 


272 Wells & Foote—One Hundred Years of Chemistry. 


sulphur crystals, and from this and other cases of 
dimorphism or of polymorphism it became evident that 
analogous compounds were not necessarily always iso- 
morphous, a circumstance which has restricted the 
application of the law to some extent. 

Besides its application in fixing analogous formulas, 
the law of isomorphism has come to be of much practical 
use in the understanding and simplification of the formu- 
las for minerals, for these natural crystals very often 
contain several isomorphous compounds in varying pro- 
portions, and an understanding of this ‘‘isomorphous 
replacement,’’ as it is called, makes it possible to deduce 
simple general formulas for them. 

In some cases isomorphism takes place to a greater or 
less extent between substances which are not chemically 
similar, and this brings about a variation in composition 
which at times has caused confusion. For instance, the 
mineral pyrrhotite has a composition which usually 
varies between Fe,S, and Fe,,8,., and both these formu- 
las have been assigned to it. It was recently shown by 
Allen, Crenshaw and Johnston in this Journal (33, 169, 
1912) that this is a case where the compound FeS is 
eapable of taking up various amounts of sulphur 
isomorphously. 

The idea of solid solution was advanced by van’t Hoff 
to explain the crystallization of mixtures, including cases 
of evident isomorphism. This view has been widely 
accepted, and it has been particularly useful in cases 
where isomorphism is not evident. Solid solution 
between metals has been found to be exceedingly com- 
mon, many alloys being of this character. A case of 
this kind was observed by Cooke and described in the 
Journal (20, 222, 1855). He prepared two well-crystal- 
lized compounds of zine and antimony to which he gave 

the formulas Zn,Sb and Zn,Sb, but he observed that 
excellent crystals of each could be obtained which varied 
largely in composition from these formulas. As the two 
compounds were dissimilar in their formulas and crys- 
talline forms, Cooke assumed that isomorphism was — 
impossible and concluded ‘‘that it is due to an actual 
perturbation of the law of definite proportions, produced 
by the influence of mass.’’? We should now regard this 
as a case of solid solution. 


Wells & Foote—One Hundred Years of Chemistry. 278 


A Lack of Confidence in Avogadro’s Principle-—One 
reason why chemists were so slow in arriving at the 
correct atomic weights and formulas was a partial loss 
of confidence in Avogadro’s principle. About 1826 the 
young French chemist Dumas devised an excellent 
method for the determination of vapor densities at high 
temperatures, and his results and those of others showed 
some discrepancies in the expected densities. For 
example, the vapor density of sulphur was found to be 
about three times too great, that of phosphorus twice too 
great, that of mercury vapor and that of ammonium 
chloride only about half large enough to correspond to 
the values expected from analogy and other considera- 
tions. Thus, one volume of oxygen with two volumes of 
hydrogen make two volumes of steam, but only one-third 
of a volume of sulphur vapor was found to unite with 
two volumes of hydrogen to make two volumes of hydro- 
gen sulphide. Berzelius saw clearly that the results 
pointed to the existence of such molecules as S,, Pi, and 
He,, but it was not generally realized in those days that 
Avogadro’s rule is fundamentally reliable, and Berzelius 
himself appears to have lost confidence in it on account 
of these complications, for he did not apply Avogadro’s 
principle to decisions about atomic weights except in the 
cases of substances gaseous at ordinary temperatures. 

Electro-chemical Theorres.— The observation was 
made by Nicholson and Carlisle in 1800 that water 
was decomposed into its constituent gases by the 
electric current. Then in 1803 Berzelius and Hisinger 
found that salts were decomposed into their bases and 
acids by the same agency, and in 1807 Davy isolated 
potassium, sodium, and other metals afterwards, by a 
similar decomposition. Since those early times a vast 
amount of attention has been paid to the relation of 
electricity to chemical changes, a relation that is evi- 
dently of great importance from the fact that while 
electric currents decompose chemical compounds, these 
eurrents, on the other hand, are produced by chemical 
reactions. 

Berzelius was particularly prominent in this direc- 
tion, and in 1819 he published an elaborate electro-chem- 
ical theory. He believed that atoms were electrically 
polarized, and that this was the cause of their combina- 
tion with one another. He extended this idea to groups 


274 Wells & Foote—One Hundred Years of Chemistry. 


of atoms, particularly to oxides, and regarded these 
groups as positive or negative, according to the excess of 
positive or negative electricity derived from their con- 
stituent atoms and remaining free. He thus arrived at 
his dualistic theory of chemical compounds, which 
attained great prominence and prevailed for a long time 
in chemical theory. According to this idea, each com- 
pound was supposed to be made up of a positive and a 
negative atom or group of atoms. For example, the for- 
mulas for potassium nitrate, calcium carbonate, and 
sulphuric acid corresponded to K,O.N,0,, CaO.CO, and 
H,O.SO; where we now write KNO,, CaCO, and H,SO,, 
and the theory was extended to embrace organic com- 
pounds also. 

The eminent English chemist and physicist Faraday 
announced the important law of electro-chemical equiva- 
lents in 1834. This law shows that the quantities of 
elements set free by the passage of a given quantity of 
electricity through their solutions correspond to the 
chemical equivalents of those elements. Faraday made a 
table of the equivalents of a number of elements, regard- 
ing them important in connection with atomic weights, 
but at that time no sharp distinction was usually made 
between equivalents and atomic weights, and it was not 
fully realized that one atom of a given element may be 
the electrical equivalent of several atoms of another. 

Faraday’s law, which is still regarded as fundamen- 
tally exact, has been of much practical use in the 
measurement of electric currents and in calculations con- 
nected with electro-chemical processes. In discussing 
his experiments, Faraday made use of several new terms, 
such as ‘‘electrolyte’’ for a substance which conducts 
electricity when in solution, and is thus ‘‘electrolyzed,’’ 
‘electrode,’’ ‘‘anode,’’ and ‘‘cathode,’’ terms that have 
come into general use, and finally ‘‘ions’’ for the parti- 
cles that were supposed to ‘‘wander’’ towards the elec- 
trodes to be set free there. 

This term ‘‘ion’’ remained in comparative obscurity 
for more than half a century, when it was brought into 
great prominence among chemists by Arrhenius in con- 
nection with the ionic theory. 

Cannizearo’s Ideas—Up to about 1869 chaos reigned 
among the formulas used by different chemists. Various 
compound radicals and numerous type-formulas were 


Wells & Foote—One Hundred Years of Chemistry. 275 


employed, dualistic and unitary formulas of several 
kinds were in use, but the worst feature of the situation 
was the fact that more than one system of atomic weights 
was in vogue, so that water might be written 

HO. tO, ‘or eo 
and similar discrepancies might appear in nearly all 
formulas containing elements of different valencies. In 
1858, however, an article by the Italian chemist Canniz- 
zaro appeared in which the outlines of a course in chem- 
ical philosophy were -presented. This acquired wide 
circulation in the form of a pamphlet at a chemical con- 
vention somewhat later, and it dealt so clearly and ably 
with Avogadro’s principle, Dulong and Petit’s law, and 
other points in connection with formulas that it led to a 
rapid and almost universal reform among those who 
were using unsatisfactory formulas. 

At about this time also the dualistic formulas of Ber- 
zelius were generally abandoned, and hydrogen came to 
be regarded as the characteristic element of all acids. 
For instance, CaO.SO.,, called ‘‘sulphate of lime,’’ came 
to be written CaSO, and was called ‘‘calcium sulphate,’’ 
and while it had been shown as early as 1815 by Davy 
that ‘‘iodic acid,’’ I,0,, showed no acid reaction until it 
was combined with water, the accumulation of similar 
facts led to the formulation of sulphuric acid as H,SO, 
instead of SO, or H,O.SO,, and that of other ‘‘oxygen 
acids’’ in a similar way. As a necessary consequence of 
this view of acids, the bases came to be regarded as com- 
pounds of the ‘‘hydroxyl’’ group, OH. Therefore the 
formula for caustic soda came to be written NaOH 
instead of Na,O.H,O, and so on. 

The Periodic System of the Elements——The perio- 
dicity of the elements in connection with their atomic 
weights was roughly grasped by Newlands in England, 
who announced his ‘‘law of octaves’’ in 1863. This was 
at the time when the atomic weights were being modified 
and their numerical relations properly shown. The sub- 
ject was worked out more fully by L. Meyer in Germany 
a little later, but it was most clearly and elaborately pre- 
sented by the Russian chemist Mendeléeff in 1869. 

In order that this subject may be explained to some 
extent Mendeléeff’s table is given here, with the addition 
of the recently discovered elements and some other mod- 
ifications. 


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Wells & Foote—One Hundred Years of Chemistry. 277 


In this table the elements arranged in the order of 
their atomic weights fall into eight groups where the 
known oxides progress regularly, with the exception of 
two or three elements, from R,O in Group I to R,O, in 
Group VII, while in Group VIII two oxides (of ruthen- 
ium and osmium) are known which carry the progression 
to RQ,. 

It was pointed out by Mendeléeff that, with the excep- 
tion of series 1 and 2 at the top of the table, the alternate 
members of the groups show particularly close relation- 
ships. These subordinate groups, marked A and B, in 
most cases show remarkable analogies and gradations in 
their properties, for example, in the alkali-metals from 
lithium to cesium, and in the halogens from fluorine to 
iodine. The two divisions of a group do not usually 
show very close relations to each other, except in their 
valency, and they even display, in several instances, 
opposite gradations in chemical activity in the order of 
their atomic weights. For instance, cesium stands at 
the electro-positive end, while gold stands at the electro- 
negative end of its subordinate group. The difference 
between the two divisions is very great in Groups VI and 
VII, but it is extreme in Group VIII, where heavy metals 
are on one side and inactive gases on the other. Many 
authorities separate these gases into a ‘‘Group O”’ by 
themselves at the left-hand side of the table, but this does 
not change their relative positions, and the plan may be 
objected to on the ground that many vacant places are 
thus left in the groups VIII and O. 

The periodic law has been useful in rectifying certain 
atomic weights. At the outset Mendeléeff was obliged to 
change beryllium from 14:5 (assuming Be,O,) to 9 
(assuming BeO), and later the atomic weights of indium 
and uranium were changed to make them fit the system. 
All of these changes have been confirmed by physical 
means. 

Mendeléeff found a number of vacant places in his 
table, and was thus able to render further service to 
chemical science by predicting the properties of undis- 
covered elements, and his predictions were very closely 
confirmed by the later discovery of scandium, gallium, 
and germanium. The table indicates that there are still 
two undiscovered elements below manganese and prob- 
ably two more among the rare-earth metals. The inter- 


278 Wells &é Foote—One Hundred Years of Chemistry. 


esting observation has just recently been made by Soddy 
that the products of radioactive disintegration appear to 
pass In a symmetrical way through positions in the 
periodic system, giving off a helium molecule at alternate 
transformations until the place of lead is reached. It 
appears, therefore, that the five vacant places in the table 
above bismuth are probably occupied by these evanes- 
cent elements, and it is to be noticed that all of the 
elements that have been placed in this region of high 
atomic weights are radioactive. | 

There are some inconsistencies in the periodie system. 
The increments in the atomic weights are irregular, and 
there are three cases, argon and potassium, cobalt and 
nickel, and tellurium and iodine, where a higher atomic 


weight is placed before a lower one in order to bring 


these elements into their undoubtedly proper places. 
There is a peculiarity also in the heavy-metal division of 
Group VIII, where three similar elements occur in each 
of three places, and where the usual periodicity appears 
to be suspended, or nearly so, in comparison with most 
of the other elements. However, there seems to be a 
still more remarkable case of this kind in Group III, 
where fourteen metals of the rare-earths have been 
placed. ,They are astonishingly similar in their chemical 
properties, hence it seems necessary to assume that 
periodicity is suspended here throughout the wide range 
of atomic weights from 139 to 174, where no elements 
save these have been found. 

Several other interesting features of the table may be 
pointed out. The chlorides and hydrides, as indicated 
by the ‘‘typical compounds,’’ show a regular progres- 
sion in both directions towards Group IV. (Where the 
type-formulas do not apply, as far as is known, to more 
than one or two elements, they have been placed in 
parentheses in the table given here.) It is a striking 
fact that the acid-forming elements occur together in a 
definite part of the table, and that the gases and other 
non-metallic elements, except the inactive gases of Group 
VIII, occur in the same region. sf 

Atomic Numbers.—As the result of a spectroscopic 
study of the wave-lengths or frequencies of the X-rays 
produced when cathode rays strike upon anti-cathodes 
composed of different elements, Moseley in 1914 discov- 
ered that whole numbers in a simple series can be 


Wells & Foote—One Hundred Years of Chemistry: 279 


attributed to the atoms. These atomic numbers are: 1 
for hydrogen, 2 for helium, 3 for lithium, 4 for beryllium, 
and so on, in the order in which the elements occur in 
Mendeléeff’s periodic table, and in the cases of argon and 
potassium, cobalt and nickel, and tellurium and iodine, 
they follow the correct chemical order, while the atomic 
weights do not. They appear to indicate, therefore, an 
even more fundamental relation between the atoms than 
that shown by the atomic weights. 

These numbers are now available for every element 
up to lead, and they are particularly interesting in indi- 
cating, on account of missing numbers, the existence of 
two undiscovered elements in the manganese group, and 
two more among the rare-earth metals, in confirmation 
of the vacant places below lead in Mendeléeff’s table. 

The Isolation of Hlements.——In the year 1818 about 
53 elements were recognized, and since that time about 
30 more have been discovered, but the elements already 
known comprised the more common ones, and nearly all 
of those which have been commercially important. A 
few of them, including beryllium, aluminium, silicon, 
magnesium, and fluorine, were then known only in their 
compounds, as they had not yet been isolated in the free 
condition. 

Berzelius in 1823 prepared silicon, a non-metallic 
element resembling carbon in many respects. This 
element has recently been prepared on a rather large 
scale in electric furnaces at Niagara Falls, and has been 
used for certain purposes in the form of castings. 

Wohler created much sensation in 1827 by isolating 
aluminium and finding it to be a very light, strong and 
malleable metal, stable in the air, and of a silver-white 
color. For a long time this metal was a comparative 
rarity, being prepared by the reduction of aluminium 
chloride with metallic sodium; but about 25 years ago 
Hall, an American, devised a method of preparing it by 
electrolyzing aluminium oxide dissolved in fused cryo- 
lite. 'Fhis process reduced the cost of aluminium to such 
an extent that it has now come into common use. 

Wohler and Bussy prepared beryllium in 1828, and 
Liebig and Bussy did the same service for magnesium in 
1830. The latter metal has come to be of much practical 
importance, both as a very powerful reducing agent in 
chemical operations, and as an ingredient of flash-light 


280 Wells & Foote—One Hundred Years of Chemistry. 


powders and of mixtures used for fireworks. It is also 
used in making certain light alloys. 

After almost innumerable attempts to isolate fluorine, 
during a period of nearly a century, this was finally 
accomplished in 1886 by Moissan in France by the elec- 
trolysis of anhydrous hydrogen fluoride. The free 
fluorine proved to be a gas of extraordinary chemical 
activity, decomposing water at once with the formation 
of hydrogen fluoride and ozonized oxygen. This fact 
explains the failure of many previous attempts to pre- 
pare it in the presence of water. 

Early Discoveries of New Elements.—The remarkable 
activity of chemical research at the beginning of our 
period is illustrated by the fact that three new elements 
were discovered in 1817. In that year Berzelius had dis- 
covered selenium, Arfvedson, working in Berzelius’s 
laboratory had discovered the important alkali-metal 
hthium, and Stromeyer had discovered cadmium. 

In 1826 Ballard in France discovered bromine in the 
mother-liquor from the crystallization of common salt 
from sea-water. Bromine proved to be an unusually 
interesting element, being the only non-metallic one that 
is liquid at ordinary temperatures, and being strikingly 
intermediate in its properties between chlorine and 
iodine. It has been obtained in large quantities from 
brines, and is produced extensively in the United States. 
The elementary substance and its compounds have found 
important applications in chemical operations, while the 
bromides have been found valuable in medicine and 
silver bromide is very extensively used in photography. 

In 1828 Berzelius discovered thorium. The oxide of 
this metal has recently been employed extensively as the 
principal constituent of incandescent gas-mantles, and 
the element has acquired particular importance from the 
fact that, like uranium, it is radio-active, decomposing 
spontaneously into other elements. 

Vanadium had been encountered as early as 1801 by 
Del Rio, who named it ‘‘erythronium,’’ but a little later 
it was thought to be identical with chromium and was lost 
sight of for a while. In 1830, however, it was re-discov- 
ered by, and received its present name from Sefstrom in 
Sweden. Berzelius immediately made an _ extensive 
study of vanadium compounds, but he gave them incor- 
rect formulas and derived an incorrect atomic weight for 


Wells € Foote—One Hundred Years of Chemistry. 281 


the element, because he mistook a lower oxide for the 
element itself. Roscoe in England in 1867 isolated 
vanadium for the first time, found the right atomic 
weight, and gave correct formulas to its compounds. 
Vanadium is particularly interesting from the fact that 
it displays several valencies in its compounds, many of 
which are highly colored. It has found important use as 
an ingredient in very small proportions in certain 
‘“‘special steels’? to which it imparts a high degree of 
resistance to rupture by repeated shocks. 

Columbium was discovered early in the nineteenth 
century in the mineral columbite from Connecticut by 
Hatchett, an Englishman, who did not, however, obtain 
the pure oxide. It was afterwards obtained by Rose who 
named it niobium. Both names for the element are in 
use, but the former has priority. Attention was called 
to this fact by an article in the Journal by Connell, an 
Englishman (18, 392, 1854). 

The Platinum Group of Metals.—In 1854 a new mem- 
ber of the platinum group of metals, ruthenium, was dis- 
covered by Claus. Platinum had been discovered about 
the middle of the 18th century, while its other rarer asso- 
ciates, iridium, osmium, palladium, and rhodium had 
been recognized in the very early years of the 19th cen- 
tury. It was during the latter period that platinum 
ware began to be employed to a considerable extent in 
chemical operations, and this use was greatly extended 
as time went on. The discovery was made by Phillips 
in 1831 that finely divided platinum by contact would 
bring about the combination of sulphur dioxide with 
atmospheric oxygen, and this application during the past 
20 years has become enormously important in the sul- 
phurie acid industry, while other important applications 
of platinum as a ‘‘catalytic agent’’ have also been made. 
Wolcott Gibbs and Carey Lea have contributed perhaps 
more than any other recent chemists to a knowledge of 
the platinum metals. Carey Lea (38, 81, 248, 1864) 
dealt chiefly with the separation of the metals from each 
other, while Gibbs’s work (31, 63, 1861; 34, 341, 1862) 
included investigations of many of the compounds. 

It may be mentioned that while platinum and its asso- 
ciates were formerly known only in the uncombined con- 
dition in nature, the arsenide sperrylite, PtAs,, was 
described by the late S. L. Penfield, and the senior writer 


282 Wells & Foote—One Hundred Years of Chemistry. 


of this chapter, in articles published in the Journal (37, 
67,11; 1889). ) 

Applications of the Spectroscope-—The discovery in 
certain mineral waters of the rare alkali-metals rubidium ° 
and cesium by Bunsen and Kirchoff in 1861 was in conse- 
quence of the application of spectroscopy by these same 
scientists a short time previously to the identification of 
elements imparting colors to the flame. Since that time 
the employment of the spectroscope for chemical pur- 
poses has been much extended, as it has been used in the 
examination of light from electric sparks and ares, as 
well as from Geissler tube discharges and from colored 
solutions. 

The metals rubidium and cesium are interesting in 
being closely analogous to potassium and in standing at 
the extreme electro-positive end of the series of known 
metals. It should be noticed here that Johnson and 
Allen of our Sheffield Laboratory, having obtained a 
good supply of rubidium and cesium material from the 
lepidolite of Hebron, Maine, made some important 
researches upon these elements, accounts of which were 
published in the Journal (34, 367, 1862; 35, 94, 1863). 
They established the atomic weight of cesium, thus cor- 
recting Bunsen’s determination which was unsatisfac- 
tory on account of the small quantity and impurity of his 
material. Pollucite, a mineral rich in cesium, which had 
been found in very small amount on the Island of EHlba, 
has more recently been obtained in large quantities—hun- 
dreds of pounds—at Paris, Maine, and its vicinity. 
This American pollucite was first analyzed and identi- 
fied by the senior writer of this article (41, 213, 1891), 
and later (43, 17, 1892 et seq.) the results of many inves- 
tigations on exsium and rubidium compounds, in which 
the junior writer played an important part, carried out 
in Sheffield Laboratory, were published in the Journal. 

The application of the spectroscope led to the discov- 
ery of thallium in 1861: by Crookes of England, and to 
that of indium in 1863 by Reich and Richter in Germany. 
Both of these metals are extremely rare, but they are of 
considerable theoretical interest. Thallium is particu- 
larly remarkable in showing resemblances in its different 
compounds to several groups of metals. 

The spectroscope was employed again in connection 
with the discovery of gallium in 1875 by Boisbaudran. 


Wells é Foote—One Hundred Years of Chemistry. 288 


It is in the same periodic group as thallium and indium, 
and it has a remarkably low melting point, just above 
ordinary room-temperature. It has been among the 
rarest of the rare elements, but within two or three years 
a source of it has been found in the United States in cer- 
tain residues from the refining of commercial zine. The 
recent issues of the Journal (41, 351, 1916; 42, 389, 1916) 
show that Browning and Uhler of Yale have availed 
themselves of this new material in order to make import- 
ant chemical and physical researches upon this metal. 

Germanum.—The discovery of germanium in the min- 
eral argyrodite in 1886 by Winkler revealed a curious 
metal which gives a white sulphide that may be easily 
mistaken for sulphur and which is volatilized completely 
when its hydrochloric acid solution is evaporated, so that 
it is evasive in analytical operations. This element had 
been predicted with much accuracy by Mendeléeff, and 
it is rather closely related to tin. 

A few years after the discovery of germanium, Pen- 
field published in the Journal (46, 107, 1893; 47, 451, 
1894) some analyses of argyrodite, correcting the for- 
mula given by Winkler to the mineral; also he described 
canfieldite, an analogous mineral from Bolivia, in which 
a large part of the germanium was replaced by tin. 

The Rare Earths——Before the year 1818 two rare 
earths, the oxides of yttrium and cerium, were known 
in an impure condition. Since that time about fourteen 
others have been discovered as associates of the first 
two. The rare earths are peculiar from the fact that 
many of them are always found mixed together in the 
minerals containing them, and also from the circum- 
stance that most of them are remarkably similar in their 
chemical reactions and consequently exceedingly difficult 
to separate from each other. In many cases multitudes 
of fractional precipitations or erystallizations are needed 
to obtain pure salts of a number of these metals. The 
solutions of the salts of several of these elements give 
characteristic absorption bands when examined spectro- 
scopically by the use of transmitted light. 

No important practical application has been found for 
any of these earthy oxides, except that about one per cent 
of cerium oxide is mixed with thorium oxide in ineandes- 
cent gas-mantles in order to obtain greatly increased 
luminosity. 


284 Wells & Foote—One Hundred Years of Chemistry. 


The Inactwe Gases.—As long ago as 1785, Cavendish, 
that remarkable Englishman who first weighed the world 
and first discovered the composition of water, actually 
obtained a little argon in a pure condition by sparking 
atmospheric nitrogen with oxygen converting it into 
nitric acid (another discovery of his) and absorbing the 
excess of oxygen. The volume of this residual gas as 
estimated by him corresponds very closely to the volume 
of argon in the atmosphere, as now known. 

It was more than a century later, in 1894, that Rayleigh 
and Ramsay discovered argon in the air. Lord Rayleigh 
had found that atmospheric nitrogen was about one-half 
per cent heavier than chemical nitrogen, a fact which led 
to the investigation. It was only necessary to repeat 
Cavendish’s experiment on a large scale, or to absorb 
oxygen with hot copper and nitrogen with hot mag- 
nesium, in order to obtain argon. The gas attracted 
much attention, both on account of having but a single 
atom in its molecule, and particularly because it failed to 
enter into chemical combination of any kind. This gas 
has been used of late for filling the bulbs of incandescent 
electric lamps in cases where a gas-pressure without 
chemical action is desired. 

In 1890 and 1891, Hillebrand published in this Journal 
40, 384, 1890: 42, 390, 1891) a series of analyses of the 
mineral uraninite and reported in some samples of the 
mineral as much as 2-5 per cent of an inactive gas. 
Hillebrand examined the gas spectroscopically but, just 
missing an important discovery, he detected only the 
spectrum lines of nitrogen. Ramsay, in searching for 
argon in some sort of natural combination, and doubt- 
less remembering Hillebrand’s work, heated some 
cleveite, a variety of uraninite, and obtained, not argon, 
but a new gas. This gave a yellow spectrum line cor- 
responding to a line previously observed in the light of 
the sun’s corona and attributed to an element in the sun 
called helium. Helium, therefore, in 1895 had been found 
on the earth. This gas is a constant constituent of 
uranium minerals, as it is produced by the breaking down 
of radioactive elements. It has been found in very small 
quantity in the atmosphere, and is the most difficult of all 
known gases to liquefy, as its boiling point, as shown hy 
Onnes in 1908, is only 4° above the absolute zero. It has 
not yet been solidified. 


Wells G Foote—One Hundred Years of Chemistry. 285 


In 1898 Ramsay and Travers, by the use of ingenious 
methods of fractional distillation and absorption by char- 
coal, obtained three other much rarer inactive gases 
from the atmosphere which they called neon, krypton and 
xenon. 

The inactive gases are all colorless, and as they form 
no chemical compounds they are characterized by their 
densities, which give their atomic weights, by their boil- 
ing points, and by their characteristic Geissler-tube spec- 
tra. 

The gaseous radium emanation, or niton, belongs also 
to the inactive group, and it was also collected and 
studied by Ramsay who was compelled to work with only 
0-0001 ec. of it, as the volume obtained by heating radium 
salts is very small. It is an evanescent element, disap- 
pearing within a few days on account of radioactive dis- 
integration. Meanwhile it glows brilliantly when lique- 
fied and cooled to the temperature of liquid air. It has 
an atomic weight of 222, four units below that of radium, 
and the difference is considered as due to the loss by 
radium of an atom of helium in passing into the 
emanation. 

The Radioactive Elements.—The discovery of radium 
in 1898 by Madame Curie, and the study of that and other 
radioactive elements has produced a profound effect 
upon chemical theory. It was found that the two ele- 
ments of the highest atomic weights, uranium and 
thorium, are always spontaneously decomposing into 
other elements at a fixed rate of speed which can be con- 
trolled by no artificial means, and that the elements 
resulting from these: decompositions likewise undergo 
spontaneous changes into stil! other elements at greatly 
varying rates of speed, forming in each case a remark- 
able series of temporary elements. These transforma- 
tions are accompanied by the emission at enormous 
velocities of three kinds of rays, one variety of which has 
been shown to consist of helium atoms. The greater 
number of the elements formed in these transformations 
have not as yet been obtained in a pure condition, and 
they are known only in connection with their radio- 
activity, volatility, ete.; but radium and niton, two of 
these products, have been obtained in a pure condition, 
so that their atomic weights and their places in the 
periodic system have been fixed. 


286 Wells &é Foote—One Hundred Years of Chemistry. 


We owe much of our knowledge of the radioactive 
transformations to the researches of Rutherford and of 
Soddy, and of their co-workers, but one of the important 
products of the transformation of uranium, an element 
which he called ionium, was characterized by Boltwood of 
Yale (25, 365, 1908). 

Radium and niton, apart from their radioactive prop- 
erties, resemble barium and the inert gases of the atmos- 
phere, respectively. The rates at which their progeni- 
tors produce them, and the rates at which they themselves 
decompose, bring about a state of equilibrium after a 
time. Therefore a given amount of uranium, which 
decomposes exceedingly slowly, can yield even after 
thousands of years only a very small proportional 
quantity of undecomposed radium, one-half of which 
disappears in about 2500 years, because the amount 
decomposed must eventually be equal to the amount pro- 
duced. The first conclusive evidence that radium is a 
product of the decomposition of uranium was given by 
Boltwood in this Journal (18, 97, 1904). He found that 
all uranium minerals contain radium; and the amount 
of radium present is always proportional to the amount 
of uranium, which shows the genetic relation between 
the two. 

In the case of niton, which is produced by radium, and 
is called also the radium emanation, the rate of decay is 
rapid, so that if the gas is expelled from radium by heat- 
ing, equilibrium is reached after a few days, with the 
accumulation of the largest possible amount of niton. 

The conclusion has been reached by Rutherford and 
others that the final product besides helium, in the radio- 
active transformations, is lead, or at least an element 
or elements resembling lead to such a degree that no 
separation of them by chemical means is _ possible. 
Atomic weight determinations by Richards and others 
have shown that specimens of lead found in radioactive 
minerals give distinctly different atomic weights from 
that of ordinary lead. This fact has led to the view that 
possibly the atoms of the elements are not all of the same 
weight, but vary within certain limits—a view that is 
contrary to previous conclusions derived from the uni- 
formity in atomic weights obtained with material from 
many different sources. 

The results of the investigations upon radioaetivity 


Wells & Foote—One Hundred Years of Chemistry. 287 


have led to modified views in regard to the stability of 
. the elements in general. There has been little or no 
proof obtained that any artificial transmutation of the 
elements is possible, but the spontaneous transformation 
of the radioactive elements brings forward the possibility 
that other elements are changing imperceptibly, and that 
a state of evolution exists among them. All of the radio- 
active changes that we know proceed from higher to 
lower atomic weights, and we are entirely ignorant of the 
process by which uranium and thorium must have been 
produced originally. 

Since radioactive changes have been found to be 
accompanied by the release of vast amounts of energy. 
compared with which the energy of chemical reactions is 
trivial, a new aspect in regard to the structure of atoms 
has arisen,—they must be complex in structure, the seats 
of enormous energy. 

The determination of the amount of radium in the 
earth’s crust has indicated that the heat produced by it is 
amply sufficient to supply the loss of heat due to radia- 
tion, and this source of heat is regarded by many as the 
eause of volcanic action. The sun’s radiant heat also 
has been supposed to be supplied by radioactive action, 
so that the older views regarding the limitation of the 
age of the earth and the solar system on account of loss of 
heat have been considerably modified by our knowledge 
of radioactivity. 


PHYSICAL CHEMISTRY. 


The application of physical methods as aids to chem- 
ical science began in early times, and some of these, such 
as the determinations of gas and vapor densities, specific 
heats, and crystalline forms have been mentioned already 
in this article. Within recent times physical chemistry 
has greatly developed and a few of its important achieve- 
ments will now be described. 

Molecular Weight Determinations —Gas and vapor 
densities in connection with Avogadro’s principle, 
formed the only basis for molecular weight determina- 
tions until comparatively recent times. The early 
methods of Gay-Lussac and Dumas for vapor density 
were supplemented in 1868 by the method of Hofmann, 
whereby vapors were measured under diminished pres- 


288 Wells & Foote—One Hundred Years of Chemistry. 


sure over mercury. In 1878 Victor Meyer introduced a 
simpler method depending upon the displacement of air 
or other gas by the vapor in a heated tube. As refrac- 
tory tubes, such as those of porcelain or even iridium, 
could be used in this method, molecular weights at 
extremely high temperatures were determined with inter- 
esting results. For instance, it was found that iodine 
vapor, which shows the molecule I, at lower tempera- 
tures, gradually becomes monatomic with rise in tem- 
perature, that sulphur vapor dissociates from 8, to 8S, 
under similar conditions, and that most of the metals, 
including silver, have monatomic vapors. 

In 1883 and later it was pointed out by Raoult that the 
molecular weights of substances could be found from the 
freezing points of their solutions, but this method was 
complicated from the fact that salts, strong acids and 
strong bases behaved quite differently from other sub- 
stances in this respect, and allowances had to be made for 
the types of substances used. The complication was 
afterwards explained by the ionization theory of Arr- 
henius. Better apparatus for this method was soon 
devised by Beckmann, who introduced also a method 
depending upon the boiling points of solutions, and these 
two methods are still the standard ones for determining 
molecular weights in solution. They are very exten- 
sively employed by organic chemists. 

It has been found that the majority of substances when 
dissolved have the same molecular weight as in the 
gaseous condition, provided that they can be volatilized 
at comparable temperatures. For instance, sulphur in 
solution has the formula S,, iodine is I, and the metals 
are monatomic. 

Van’t Hoff’s Law and Arrhenius’s Theory of lons.— 
Modern views on solutions date largely from 1886, when 
van’t Hoff called attention to the relations existing 
between the osmotic pressure exerted by dissolved sub- 
stances and gas pressure. | 

Pfeffer, a botanist,:was the first to measure osmotic 
pressure (1877). Basing his conclusions chiefly upon 
Pfeffer’s determinations, van’t Hoff formulated a new 
and highly important law, which may be stated as fol- 
lows: The osmotic pressure exerted by a substance in 
solution is equal to the gas pressure that the substance 
would exert if it were a gas at the same temperature and 


Wells € Foote—One Hundred Years of Chemistry. 289 


the same volume. Further investigations have fully 
established the fact that molecules in dilute solution obey 
the simple laws of gases. 

It was pointed out by van’t Hoff that salts, strong 
acids and strong bases showed marked exceptions to his 
law in exerting much greater osmotic pressures than 
those calculated for them. 

The next year in 1887, Arrhenius explained this abnor- 
mal behavior of salts, strong acids and strong bases by 
assuming that they dissociate spontaneously into ions 
when they dissolve, and that these more numerous par- 
ticles act like molecules in producing osmotic pressure. 
He showed that these exceptional substances all conduct 
electricity in solution, while those conforming with van’t 
Hoff’s law do not, and according to his theory the ions 
become positively or negatively charged when they are 
formed, and these charged ions conduct the current. 
For example a molecule of sodium chloride was supposed 
to give the two ions Nat and Cl-, thus exerting twice as 
much osmotic pressure as a single molecule. 

Determinations of osmotic pressure or related values, 
such as depression of the freezing point and of electric 
conductivity, indicated that ionization could not be 
regarded as complete in any case except in exceedingly 
dilute solutions, and that the extent of ionization varied 
with different substances. The fact that osmotic pres- 
sures and electric conductivities gave closely agreeing 
results in regard to the extent of ionization in various 
cases, is the strongest evidence in support of the theory. 

It was difficult at first for many chemists to believe 
that atoms, such as those of sodium and chlorine, and 
eroups such as NH, and SO, could exist independently 
in solution, even though electrically charged. However, 
the theory rapidly gained ground and is now accepted 
by nearly every chemist as a satisfactory explanation of 
many facts. 

During recent years, many investigations relating to 
osmotic- pressure and ionization have been carried out in 
the United States, but only the work of Morse, A. A. 
Noyes, and the late H. C. Jones can be merely alluded to 
here. It should be mentioned that the eminent author 
of the ionic hypothesis gave the Silliman Memorial course 
of lectures at Yale in 1911 on Theories of Solution. 


Am. Jour. Sct.—FourtH Series, Vou. XLVI, No. 271.—Juty, 1918. 


290 Wells & Foote—One Hundred Years of Chemistry. 


Colloidal Solutions —Graham, an English chemist, in 
1861 was the first to make a distinction between sub- 
stances forming true solutions, which he called erystal- 
loids, and those of a gummy nature resembling glue, 
which in solution do not diffuse readily through parch- 
ment membranes, as crystalloids do, and which he ealled 
colloids. The separation of colloids by means of parch- 
ment was called dialysis, and this process has come into 
extensive use in preparing pure colloidal solutions. 
Slow diffusion 1s now regarded as characteristic of col- 
loids rather than their gummy condition. 

Colloidal solutions occupy an intermediate position 
between true solutions and suspensions, resembling one 
or the other according to the kind of colloid and the fine- 
ness of division. By preparing filters with pores of 
varying degrees of fineness, Bechold has been able to 
separate colloids from each other in accordance with the 
size of their particles. It has also been possible to pre- 
pare different solutions of a colloid varying gradually 
from one in which the particles were undoubtedly in sus- 
pension to one which had many of the oe es of a 
true solution. 

Beginning in 1889, Carey Lea described in he Journal 
(37, 476, 1889 et seq. ) a variety of methods for preparing 
colloidal solutions of the metals, consisting in general of 
treating solutions of metallic salts with mild reducing 
agents. His work on colloidal silver was particularly 
extensive and interesting. Solutions of this kind have 
recently yielded some extremely interesting results by 
means of the ultra-microscope, an apparatus devised by 
Zsigmondy and Siedentopf. A very intense beam of 
light is passed through the solution and observed at right 
angles with a powerful microscope. Under these condi- 
tions, particles much too small to be seen by other means, 
reveal their presence by reflected light. It has been pos- 
sible in a very dilute solution of known strength to count 


_ the particles and thus to calculate their size. The small- 


est colloidal particles measured in this way were of gold 
and were shown to have approximately ten times the 
diameter, or 1000 times the volume, attributed to ordi- 
nary molecules. It is of interest that the particles 
appear in rapid motion corresponding to the well-known 
Brownian movement. 

The chemistry of colloids has now assumed such 


Wells & Foote—One Hundred Years of Chemistry. 291 


importance that it may be considered as a separate 
branch of the science. It has its own technical journal 
and deals largely with the chemistry of organic products. 
All living matter is built up of colloids, and heamogoblin, 
starch, proteins, rubber and milk are examples of col- 
loidal substances or solutions. Among inorganic sub- 
stances, many sulphides, silicic acid, and the amorphous 
hydroxides, like ferric hydroxide, frequently act as 
colloids. 

Law of Mass-Action.—Berthollet about the beginning 
of the last century was the first chemist to study the 
effect of mass, or more correctly, the concentration of 
substances on chemical action. His views summarized 
by himself are as follows: ‘‘The chemical activity of a 
substance depends upon the force of its affinity and upon 
the mass which is present in a given volume.’’ The 
development of this idea, which is fundamentally correct, 
was greatly hindered by the fact that Berthollet drew the 
incorrect conclusion that the composition of chemical 
compounds depended upon the masses of the substances 
combining to produce them, a conclusion in direct con- 
tradiction to the law of definite proportions, and since 
this view was soon disproved by Proust and others, 
Berthollet’s law in its other applications received no 
immediate attention. Mitchell, however, pointed out 
in the Journal (16, 234, 1829) the importance of 
Berthollet’s work, and Heinrich Rose in 1842 again 
called attention to the effect of mass, mentioning as one 
illustration the effect of water and carbonic acid ‘in 
decomposing the very stable natural silicates. Some- 
what later several other chemists made important contri- 
butions to the question of the influence of concentration 
upon chemical action, but it was the Norwegians, Guld- 
berg and Waage, who first formulated the law of mass 
action in 1867. 

This law has been of enormous importance in chemical 
theory, since it explains a great many facts upon a 
mathematical basis. It apples particularly to equilib- 
rium in reversible reactions, where it states that the 
product of the concentrations on the one side of a simple 
reversible equation bears a constant relation to the 
products of the concentrations on the other side, provided 
that the temperature remains constant. In eases of this 
kind where two gases or vapors react with two solids, 


292 Wells & Fovote—One Hundred Years of Chemistry. 


the latter if always in excess may be regarded as con- 
stant in concentration, and the law takes on a simpler 
aspect in applying only to the concentrations of the 
gaseous substances. For example, in the reversible 
reaction 


38Fe + 4H,O 2 Fe,0, + 4H, 


which takes place at rather high temperatures, a definite 
mixture of steam and hydrogen at a definite temperature 
will cause the reaction to proceed with equal rapidity in 
both directions, thus maintaining a state of equilibrium, 
provided that both iron and the oxide are present in 
excess. If, however, the relative concentrations of the 
hydrogen and steam are changed, or even if the tempera- 
ture is changed, the reaction will proceed faster in one 
direction than in the other until equilibrium is again 
attained. 

The principle of mass-action also explains why it is 
sometimes possible for a reversible reaction to become 
complete in either direction. For instance, in connec- 
tion with the reaction that has just been considered, if 
steam is passed over heated iron and if hydrogen is 
passed over the heated oxide, the gaseous product in each 
case is gradually carried away, and the reaction contin- 
ually proceeds faster in one direction than in the other 
until it is complete, according to the equations 


3Fe + 4H,O ——> 3Fe,0, + 4H, and 
Fe,O, + 4H, —~> 3Fe + 4H,0. 


Many other well-known and important facts, both 
chemical and physical, depend upon this law. It explains 
the circumstance that a vapor-pressure is not dependent 
upon the amount of the liquid that is present; it also 
explains the constant dissociation pressure of calcium 
carbonate at a given temperature, irrespective of the 
amounts of carbonate and oxide present; in connection 
with the ionic theory, it furnishes the reason for the 
variable solubility of salts due to the presence of elec- 
trolytes containing ions in common; and it elucidates 
Henry’s law which states that the solubilities of gases are 
proportional to their pressures. 

Ostwald, more than any other chemist, has been instru- 
mental in making general applications of this law, and he 
made particularly extensive use of it in connection with 


Wells & Foote—One Hundred Years of Chemistry. 298 


analytical chemistry in a book upon this subject which he 
published. 

The Phase Rule——In 1876 Willard Gibbs of Yale pub- 
lished a paper in the Proceedings of the Connecticut 
Academy of Science on the ‘‘Kquilibrium of Heteroge- 
neous Substances,’’ and two years later he published an 
abstract of the article in the Journal (16, 441, 1878). He 
had discovered a new law of nature of momentous 
importance and wide application which is called the 
‘‘Phase-Rule’’ and is expressed by a very simple 
formula. 

The application of this great discovery to chemical 
theory was delayed for ten years, partly, perhaps, 
because it was not sufficiently brought to the attention of 
chemists, but largely it appears because it was not at 
first understood, since its presentation was entirely 
mathematical. 

It was Rooseboom, a Dutch chemist, who first applied 
the phase-rule. It soon attracted profound attention, 
and the name of Willard Gibbs attained world-wide fame 
among chemists. When Nernst, who is perhaps the most 
eminent physical chemist of the present time, was deliv- 
ering the Silliman Memorial Lectures at Yale a few years 
ago, he took occasion to place a wreath on the grave of 
Willard Gibbs in recognition of his achievements. 

To understand the rule, it is necessary to define the 
three terms, introduced by Gibbs, phase, degrees of free- 
dom and component. 

By the first term, is meant the parts of any system of 
substances which are mechanically separable. For 
instance, water in contact with its vapor has two phases, 
while a solution of salt and water is composed of but one. 
The degrees of freedom are the number of physical con- 
ditions, including pressure, temperature and concentra- 
tion, which can be varied independently in a system 
without destroying a phase. The exact definition of a 
component is not so simple, but in general, the com- 
ponents of a system are the integral parts of which it is 
composed. Any system made up of the compound H.O, 
for instance, whether as ice, water or vapor, contains but 
one component, while a solution of salt and water con- 
tains two. Letting P, F. and C stand for the three terms, 
the phase-rule is simply 

Re 09 -P 


294 Wells & Foote—One Hundred Years of Chemistry. 


that is, the number of degrees of freedom in a system in 
equilibrium equals the number of components, plus two, 
minus the number of phases. The rule can be easily 
understood by means of a simple illustration. In a sys- 
tem composed of ice, water and water-vapor, there are 
three phases and one component and therefore 
Be 19 = 3 0 

Such a system has no degrees of freedom. This means 
that no physical condition, pressure or temperature can 
be varied without destroying a phase, so that such a sys- 
tem can only exist in equilibrium at one fixed tempera- 
ture, with a fixed value for its vapor-pressure. 

For instance, if the system is heated above the fixed 
temperature, ice disappears and if the pressure is raised, 
vapor is condensed. If this same system of water alone 
contains but two phases, for instance, liquid and vapor, 
KF —1-+ 2—2—1, or there is one degree of freedom. 
In such a system, one physical condition such as tempera- 
ture can be varied independently, but only one, without 
destroying a phase. For instance, the temperature may 
be raised or lowered, but for every value of temperature 
there is a corresponding value for the vapor pressure. 
One is a function of the other. If both values are varied 
independently, one phase will disappear, either vapor 
condensing entirely to water or the reverse. Finally if 
the system consists of one phase only, as water vapor, 
F — 2, or the system is divariant, which means that at 
any given temperature it is possible for vapor to exist at 

varying pressures. 

The illustration which has been given relates to physt- - 

eal equilibrium, but the rule is applicable to cases involy- 
ing chemical changes as well. In comparing the 
phase- rule with the la of mass action, it will be noticed 
that both have to do with equilibrium. The great advan- 
tage of the former is that it is entirely independent of the 
molecular condition of the substances in the different 
phases. For instance, it makes no difference so far as 
the application of the rule is concerned, whether a sub- 
stance in solution is dissociated, undissociated or com- 
bined with the solvent. In any ease, the solution 
constitutes one phase. On the other hand, the rule is 
purely qualitative, giving information only as to whether 
a given change in conditions is possible. The law of 
mass action is a quantitative expression so that when the 


Wells € Foote—One Hundred Years of Chemistry. 295 


value of the constant is once known, the change can be 
calculated which takes place in the entire system if the 
concentration of one substance is varied. The law, how- 
ever, requires a knowledge of the molecular condition of 
the reacting substances, which may be uncertain or un- 
known, and chiefly on this account it has, like the phase- 
rule, often only a qualitative significance. 

The phase rule has served as a most valuable means 
of classifying systems in equilibrium and as a guide in 
determining the possible conditions under which such 
systems can exist. As illustrations of its practical apph- 
cation, van’t Hoff used it as an underlying principle in 
his investigations on the conditions under which salt 
deposits have been formed in nature, and Rooseboom was 
able by its means to explain the very complicated rela- 
tions existing in the alloys of iron and carbon which form 
the various grades of wrought iron, steel and cast iron. 

Thermochemistry.—This branch of chemistry has to 
do with heat evolved or absorbed in chemical reactions. 
It is important chiefly because in many eases it furnishes 
the only measure we have of the energy changes involved 
in reactions. To a great extent, it dates from the dis- 
covery by Hess in 1840 of a fundamental law which states 
that the heat evolved in a reaction is the same whether it 
takes place in one or in several stages. This law has 
made it possible to calculate the heat values of a large 
number of reactions which cannot be determined by 
direct experiment. 

Thermochemistry has been developed by a compara- 
tively few men who have contributed a surprisingly 
large number of results. Favre and Silbermann, begin- 
ning shortly after 1850, improved the apparatus for eee 
orimetric determinations, which is called the calorimeter, 
and published many results. At about the same time 
Julius Thomsen, and in 1873 Berthelot, began their 
remarkable series of publications which continued until 
recently. Thomsen’s investigations were published in 
1882 in 4 volumes. It is probably safe to say that the 
ereater part of the data of thermochemistry was obtained 
by these two investigators. The bomb calorimeter. an 
apparatus for determining heat values by direct combus- 
tion, was developed by Berthelot. The recent work of 
Mixter at Yale, published in this Journal, and of Rich- 
ards at Harvard should be mentioned particularly. 


296 Wells & Foote—One Hundred Years of Chemistry. 


Mixter’s work in this field began in 1901 (12, 347). 
Using an improved bomb calorimeter, he has developed a 
method of determining the heats of formation of oxides 
by combustion with sodium peroxide. By this same 
method as well as by direct combustion in oxygen, he has 
obtained results which appear to equal or excel in accu- 
racy any which have ever been obtained in his field of 
work. Richards’s work has consisted largely of improve- 
ments in apparatus. He developed the so-called adia- 
batic calorimeter which practically eliminates one of the 
chief errors in thermal work caused by the heating or 
cooling effect of the surroundings. This modification is 
being generally adopted where extremely accurate work 
is required. 


ORGANIC CHEMISTRY. 


One hundred years ago qualitative tests for a few 
organic compounds were known, the elements usually 
occurring in them were recognized, and some of them had 
been analyzed quantitatively, but organic chemistry was 
far less advanced than inorganic, and almost the whole of 
its enormous development has taken place during our 
period. 

Berzelius made a great advance in the subject by estab- 
lishing the fact, which had been doubted previously, that 
the elements in organic compounds are combined in con- 
stant, definite proportions. In 1823 Liebig brought to 
light the exceedingly important fact of isomerism by 
showing that silver fulminate had the same percen- 
tage composition as silver cyanate, a compound of very 
different properties. Isomeric compounds with identical 
molecular weight as well as the same composition have 
since been found in very many cases, and they have 
played a most important part in determining the 
arrangements of atoms in molecules. They have been 
found to be very numerous in many cases. For instance, 
three pentanes with the formula C,;H,, are known, all 
that are possible according to theory, and in each case 
the structure of the molecule has been established. On 
theoretical grounds it has been calculated that 802 
isomeric compounds with the formula C,.H,, are possi- 
ble, while with more complex formulas the numbers of 
isomers may be very much greater. : 


Wells & Foote—One Hundred Years of Chemistry. 29% 


A particularly interesting case of isomerism was 
observed by Wohler in 1828, when he found that ammo- 
nium cyanate changes spontaneously into urea 


(NH,CNO —> N,H,CO). 


This was the first synthesis of an organic compound from 
inorganic material, and it overthrew the prevailing view 
that vital forces were essential in the formation of 
organic substances. A great many natural organic com- 
pounds have been made artificially since that time, and 
some of them, such as artificial alizarin, indigo, oil of 
wintergreen, and vanillin, have more or less fully 
replaced the natural products. The preparation of a 
vast number of compounds not known in nature, many of 
which are of practical importance as medicines, dyes, 
explosives, etc., has been another great achievement of 
organic chemistry. 

The development of our present formulas for organic 
compounds, by means of which in many eases the rela- 
tive positions of the atoms can be shown with the great- 
est confidence, has been gradual. Formulas based on the 
dualistic idea of Berzelius were used for some time, type 
formulas, with the employment of compound radicals, 
came later, the substitution of atoms or groups of atoms 
for others in chemical reactions came to be recognized, 
but one of the most important steps was the recognition 
of the quadrivalence of carbon and the general applieca- 
tion of valency to atoms by Kekulé about 1858. This led 
directly to the use of modern structural formulas which 
have been of the greatest value in the theoretical inter- 
pretation of organic reactions. It was Kekulé also who 
proposed the hexagonal ring-formula for benzene, C,H, 
which led to exceedingly important theoretical and prac- 
tical developments. The details of the formulas for 
many other rings and complex structures have been estab- 
lished since that time, and there is no doubt that the 
remarkable achievements in organic chemistry during the 
past sixty years have been much facilitated by the use of 
these formulas. : 

Many important researches in organic chemistry have 
been carried out in the United States, and the activity in 
this direction has greatly increased in recent vears. In 
this connection the large amount of work of this kind 
accomplished in the Sheffield Laboratory, at present 


298 Wells & Foote—One Hundred Years of Chemistry. 


under the guidance of Professor T. B. Johnson, should be 
mentioned. 

It has happened that comparatively few publications 
on organic chemistry have appeared in the Journal,. but 
it may be stated that the preparation of chloroform and 
its physiological effects were described by Guthrie (21, 
64, 1832). Unknown to him, it had been prepared by 
Souberain, a French chemist, the previous year, but the 
former was the first to describe its physiological action. 
Silliman gave a sample to Doctor Eli Ives of the Yale 
Medical School, who used it to relieve a case of asthma. 
This was the first use of chloroform in medical practice 
(21, 405, 1832). Guthrie also described in the Journal 
(21, 284, 1832) his new process for converting potato 
starch into glucose, a method which is essentially the 
same as that used to-day in converting cornstarch into 
glucose. Lawrence Smith (43, 301, 1842 et seq.), Hors- 
ford (3, 369, 1847 et seq.), Sterry “Hunt (7, 399, 1849), 
Carey Lea (26, 379, 1858 et seq.), Remsen (5, 179, 1873 et 
seq.), and others have contributed articles on ‘organic 
chemistry. 


AGRICULTURAL CHEMISTRY. 


Until near the middle of the nineteenth century, it was 
believed that plants, like animals, used organic matter for 
food, and depended chiefly upon the humus of the soil 
for their growth. This view was held even long after it 
was known that plant leaves absorb carbon dioxide and 
give off oxygen, and after the ashes of plants had been 
accurately analyzed. 

This incorrect view was overthrown by the celebrated 
German chemist, Liebig, who made many investigations 
upon the subject, and, properly interpreting previous 
knowledge, published a book in 1840 upon the applica- 
tion of chemistry to agriculture and physiology in which 
he maintained that the nutritive materials of all green 
plants are inorganic substances, namely, carbon dioxide, 
water, ammonia (nitrates), sulphates, phosphates, silica, 
lime, magnesia, potash, iron, and sometimes common salt. 
He drew the vastly important conclusion that the effective 
fertilization of soils depends upon replenishing the 
inorganic substances that have been exhausted by the 
crops. 

The fundamental principles set forth by Liebig have 


Wells & Foote—One Hundred Years of Chemistry. 299 


been confirmed, and it has been found that the fertilizing 
constituents most commonly lacking in soils are nitrogen 
compounds, phosphates, and potassium salts, so that 
these have formed the important constituents of artificial 
fertilizers. Liebig himself found that humus is valuable 
in soils, because it absorbs and retains the soluble salts. 

The foundation established by Liebig in regard to arti- 
ficial fertilizers has led to an enormous application of 
these materials, much to the advantage of the world’s 
food-supply. 

It was Liebig’s belief, in accordance with the prevail- 
ing views, that decay and putrefaction as well as 
alcoholic and other fermentations were spontaneous 
processes, and when the eminent French chemist, Pas- 
teur, in 1857, explained fermentation as directly caused 
by yeast, an epoch-making discovery which led to the 
explanation of decay and putrefaction by bacterial action 
and to the germ-theory of disease, the explanation was 
violently opposed by Liebig and other German chemists. 
Pasteur’s view prevailed, however, and since that time 
it has been found that various kinds of bacteria are 
responsible for the formation of ammonia from nitro- 
genous organic matter and also for the change of ammo- 
nia into the nitrates that are available as plant-food. 

The long-debated question as to the availability of 
atmospheric nitrogen for plant-food was settled in 1886 
by the discovery of Hellriegel that bacteria contained in 
nodules on the roots, especially of leguminous plants, are 
eapable of bringing nitrogen into combination and fur- 
nishing it to the plants. 

No more than an allusion can be made to agricultural 
experiment stations where soils, fertilizers, foods and: 
other products are examined, and where other problems 
connected with agriculture are studied. 

The late S. W. Johnson of Yale studied with Liebig 
and subsequently did much service for agricultural chem- 
istry in this country, by his investigations, his teaching, 
and his writings. His book, ‘‘How Crops Grow,’’ pub- 
lished in 1868, gave an excellent account of the principles 
of agricultural chemistry. He did much to bring about 
the establishment of agricultural experiment stations in 
this country, and for a long time he was the director of 
the Connecticut Station. 

In the Journal, as early as 1827, Amos Eaton (12, 370) 


300 Wells & Foote—One Hundred Years of Chemistry. 


published a simple method for the mechanical analysis 
of soils to determine their suitability for wheat-culture, 
and Hilgard, between 1872 and 1874, described an elab- 
orate study of soil-analysis. J. P. Norton, a Yale 
professor, in 1847 (3, 322) published an investigation 
on the analysis of the oat, which was awarded a prize of 
fifty sovereigns by a Scotch agricultural society, while 
Johnson, Atwater, and others have contributed articles 
on the analysis of various farm products. 


INDUSTRIAL ACIDS AND ALKALIES, 


One hundred years ago sulphuric acid was manufac- 
tured on a comparatively very small scale in lead 
chambers. In 1818, an English manufacturer of the 
acid introduced the modern feature of using pyrites in 
the place of brimstone, while the Gay-Lussae tower in 
1827 and the Glover tower in 1859 began to be applied as 
great improvements in the chamber process. Within 
about twenty years the contact process, employing plat- 
inized asbestos, has replaced the old chamber process to 
a large extent. It has the advantage of producing the 
concentrated acid, or the fuming acid, directly. 

During our period the manufacture of sulphuric acid 
has increased enormously. Very large quantities of it 
have been used in connection with the Leblane soda pro- 
cess in its rapid development. It came to be employed 
extensively for absorbing ammonia in the illuminating- 
gas industry, which was in its infancy one hundred years 
ago. New industries such as the manufacture of ‘‘super- 
phosphates’’ as artificial fertilizers, the refining of petro- 
leum, the manufacture of artificial dyestuffs and many 
other modern chemical products have greatly increased 
the demand for it, while its employment in the production 
of nitric and other acids, and for many other purposes 
not already mentioned, has been very great. 

The manufacture of nitric acid has been greatly 
extended during our period on account of its employment 
for producing explosives, artificial dyestuffs, and for 
many other purposes. Chile saltpeter became available 
for making it about 1852. This acid has been manufac- 
tured recently from atmospheric nitrogen and oxygen by 
combining them by the aid of powerful electric dis- 
charges. This process has been used chiefly in Norway 
where water-power is abundant, as it requires a large 
expenditure of energy. A still more recent method for: 


Wells & Foote—One Hundred Years of Chemistry. 301 


the production of nitric acid depends upon the oxidation 
of ammonia by air with the aid of a contact substance, 
such as platinized asbestos. 

The production of ammonia, which was very small a 
hundred years ago, has been vastly increased in connec- 
tion with the development of the iluminating-gas indus- 
try and the employment of by-product coke ovens. This 
substance 1s very extensively used in refrigerating 
machines and also in a great many chemical operations, 
including the Solvay soda-process. Ammonium salts 
are of great importance also as fertilizers in agriculture. 
The conversion of atmospheric nitrogen into ammonia 
on a commercial scale is a recent achievement. It has 
been accomplished by heating calcium carbide, an elec- 
tric-furnace product made from lime and coke, with nitro- 
gen gas, thus producing calcium cyanamide, and then 
treating this cyanamide with water under proper condi- 
tions. Another method devised by Haber consists in 
directly combining nitrogen and hydrogen gases under 
high pressure with the aid of a contact substance. 

Leblane’s method for obtaining sodium carbonate from 

sodium chloride by first converting the latter into the 
sulphate by means of sulphuric acid and then heating the 
sulphate with lime and coal in a furnace was invented 
as early as 1791, but it was not rapidly developed and did 
not gain a foothold in England until 1826 on account of a 
high duty on salt up to that time. Afterwards the 
process flourished greatly in connection with the sul- 
phurie acid industry upon which it depended, and with 
the bleaching-powder industry which utilized the hydro- 
chlorie acid incidentally produced by it, and, of course, 
in connection with soap manufacture and many other 
industries in which the soda itself was employed. 
- About 1866 the Solvay process appeared as a rival to 
the Leblanc process. This depends upon the precipita- 
tion of sodium bicarbonate from salt solutions by means 
of carbon. dioxide and ammonia, with the subsequent 
recovery of the ammonia. It has displaced the older 
process to a large extent, and it is carried on extensively 
in this country, for instance, at Syracuse, New York. 

Other processes for soda depend upon the electrolysis 
of sodium chloride solutions. In this case caustic soda 
and chlorine are the direct products, and the chlorine 
thus produced and liquified by pressure in steel cylinders, 
has become an important commercial article. 


802 Wells ¢ Foote—One Hundred Years of Chemistry. 


In earlier times wood-ashes were the source of potash 
and potassium salts. Wurtz in the Journal (10, 326, 


' 1850) suggested the availability of New Jersey green- 


sand as a source of potash and showed how this mineral 
could be decomposed, but it does not appear that this 
mineral has ever been utilized for the purpose. Ahout 
1861 the German potash-salt deposits began to be devel- 
oped, and these have since become the chief source of 
this material. At present many efforts are being made 
to obtain potassium compounds from other sources, such 
as brines, cement-kiln dust, and feldspar and other min- 
erals but thus far the results have not satisfied the 
demand. 


CONCLUSION. 


This account of chemical progress has given only a 
limited view of small portions of the subject, because the 
amount of available material is so vast in comparison 
with the space allowed for its presentation. Since the 
Journal has published comparatively lttle organic chem- 
istry, it was decided to make room for a better presenta- 
tion of other things by giving only a brief discussion of 
this exceedingly active and important branch of the 
science. For similar reasons industrial and metallurgi- 
eal chemistry, and other branches besides, in spite of 
their great growth and importance, have been neglected, 
except for some incidental references to them, and some 
account of a few of the more important industrial 
chemicals. 

It appears that we have much reason to be proud of the 
advances in chemistry that have been made during the 
Journal’s period, and of the part that the Journal has 
taken in connection with them, and there seems to be no 
doubt that this progress has not diminished during more 
recent times. 

The present tendency of chemical research is evidently 
towards a still greater development of organic chemis- 
try, and an increased application of physics and mathe- 
matics to chemical theory and practice. 

The very great improvements that have been made in 
ehemical education, both in the number of students and 
the quality of instruction, during the period under dis- 
cussion, and particularly in rather recent times, gives 
promise for excellent future progress. 


L. Page—A Century’s Progress m Physics. 303 


Art. X.—A Century’s Progress m Physics; 
by LricH Paces. 


Dynamics.—At the beginning of the nineteenth cen- 
tury mechanics was the only major branch of physical 
science which had attained any considerable degree of 
development. Two centuries earlier, Galileo’s experi- 
ments on the rate of fall of iron balls dropped from the 
top of the Leaning Tower of Pisa, had marked the origin 
of dynamics. He had easily disproved the prevalent 
idea that even under conditions where air resistance is 
neghgible heavy bodies would fall more rapidly than 
light ones, and further experiments had led him to con- 
clude that the increase in velocity 1s proportional to the 
time elapsed, and not to the distance traversed, as he had 
at first supposed. Less than a century later Newton had 
formulated the laws of motion in the same words in 
which they are given to-day. These laws of motion, 
coupled with his discovery of the law of universal gravi- 
tation, had enabled him to correlate at once the planetary 
notions which had proved so puzzling to his predecessors. 
His success gave a tremendous stimulus to the develop- 
ment and extension of the fundamental dynamical prin- 
ciples that he had brought to light, which culminated in 
the work of the great French mathematicians, Lagrange 
and Laplace, a little over a hundred years ago. 

Newton’s laws of motion, it must be remembered, 
apply only to a particle, or to those bodies which can be 
treated as particles in the problem under consideration. 
In his ‘‘Méeanique Analytique’’ Lagrange extended 
these principles so as to make it possible to treat the 
motion of a connected system by a method almost as sim- 
ple as that contained in the second law of motion. 
Instead of three scalar equations for each of the innumer- 
ably large number of particles involved, he showed how 
to reduce the ordinary dynamical equations to a number 
equal-to that of the degrees of freedom of the system. 
This is made possible by a combination of d’Alembert’s 
principle, which eliminates the forces due to the connec- 
tions between the particles, and the principle of virtual 
work, which confines the number of equations to the num- 
ber of possible independent displacements. The aim of 
Lagrange was to make dynamics into a branch of 


304 L. Page—A Centiury’s Progress in Physics. 


analysis, and his success may be inferred from the fact 
that not a single diagram or geometrical figure is to be 
found in his great work. 

Celestial Mechanics.—Almost simultaneously with the 
publication of the ‘‘Mécanique Analytique’’ appeared 
Laplace’s ‘‘Mécanique Céleste.’’ Laplace’s avowed 
aim was to offer a complete solution of the great 
dynamical problem involved in the solar system, taking 
into account, in addition to the effect of the sun’s gravi- 
tational field, those perturbations in the motion of each 
planet caused by the approach and recession of its 
neighbors. So successful was his analysis of planetary 
motions that his contemporaries believed that they were 
not far from a complete explanation of the world on 
mechanical principles. Laplace himself was undoubt- 
edly convinced that nothing was needed beyond a 
knowledge of the masses, positions, and initial velocities 
of every material particle in the universe in order to 
completely predetermine all subsequent motion. 

The greatest triumph of these dynamical methods was 
to come half a century later. The planet Uranus, dis- 
covered in 1781 by the elder Herschel, was at that time 
the farthest known planet from the sun. But the orbit 
of Uranus was subject to some puzzling variations. 
After sifting all the known causes of these disturbances, 
Leverrier in France and Adams in England independ- 
ently reached the conclusion that another planet still 
more remote from the sun must be responsible, and com- 
puted its orbit. Leverrier communicated to Galle of 
Berlin the results of his calculations, and during the next 
few days the German astronomer discovered Neptune 
within one degree of its predicted position! 

We shall mention but one other achievement of the 
methods of celestial mechanics. Those visitors of the 
skies, the comets, which become so prominent only to fade 
away and vanish perhaps forever, had interested astron- 
omers from the earliest times. Soon after the discovery 
of the law of gravitation, Newton had worked out a 
method by which the elements of a comet’s orbit can be 
computed from observations of its position. It was 
found that the great majority of these bodies move in 
nearly parabolic paths and only a few in ellipses. Of the 
latter the most prominent is the brilliant comet first 
observed by Halley in 1681. It has reappeared regu- 


L. Page—A Century’s Progress m Physics. 305 


larly at intervals of seventy-six years; the last appear- 
ance in the spring of 1910 is no doubt well remembered 
by the reader. Kant had considered comets to be 
formed by condensing solar nebule, whereas Laplace had 
maintained that they originate in matter which is scat- 
tered throughout stellar space and has no connection 
with the solar system. A study of the distribution of 
inclinations of comet orbits by H. A. Newton (16, 165, 
1878) of New Haven substantiated Laplace’s hypothesis, 
and led to the conclusion that the periodic comets have 
been captured by the attraction of those planets near to 
which they have passed. Of these comets a number 
have comparatively short periods, and are found to have 
orbits which are in general only slightly inclined to those 
of the planets, and are traversed in the same direction. 
Moreover, the fact that the orbit of each of these comets 
comes very close to that of Jupiter made it seem probable 
that they have been attached to the solar system by the 
attraction of this planet. Further confirmation of this 
hypothesis was furnished by H. A. Newton’s (42, 183 and 
482, 1891) explanation of the small inclination of their 
orbits and the scarcity of retrograde motions among 
them. 

In 1833 occurred one of the greatest meteoric showers 
of history. Olmstead (26, 132, 1834) and Twining (26, 
320, 1834) of New Haven noticed that these shooting 
stars traverse parallel paths, and were the first to sug- 
gest that they must be moving in swarms in a permanent 
orbit. From an examination of all accessible records, 
H. A. Newton (37, 377, 1864; 38, 53, 1864) was able to 
show that meteoric showers are common in November, 
and of particular intensity at intervals of 33 or 34 years. 
He confidently predicted a great shower for Nov. 18th, 
1866, which not only actually occurred but was followed 
by another a year later, showing that the meteoric swarm 
extended so far as to require two years to cross the 
earth’s orbit. H. A. Newton (36, 1,:1888) in America 
and Adams in Kngland took up the study of meteoric 
orbits with great interest, and the former concluded that 
these orbits are in every sense similar to those of the 
periodic comets, implying that a swarm of meteors 
originates in the disintegration of a comet. In fact 
Schiaparelli actually identified the orbit of the Perseids, 
or August meteors, with Tuttle’s comet of 1862, and 


306 L. Page—A Century’s Progress in Physics. 


shortly after the orbit of the Leonids, or November | 
meteors, was found to be the same as that of Tempel’s 
comet. 

Electromagnetism.—During the eighteenth century 
much interest had been manifested in the study of elec- 
trostatics and magnetism. Du Fay, Cavendish, Michell 
and Coulomb abroad and Franklin in America had sub- 
jected to experimental investigation many of the phe- 
nomena of one or both of these sciences, and in the early 
years of the nineteenth century Poisson developed to a 
remarkable extent the analytical consequences of the law 
of force which experiment had revealed. Both Laplace 
and he made much use of the function to which Green 
gave the name ‘‘potential’’ in 1828, and which is such a 
powerful aid in solving problems involving magnetism 
or electricity at rest. 

Meantime electric currents had been began under the 
hand of the experimenter by the discoveries of Galvani 
and Volta. Large numbers of cells were connected in 
series, and interest seemed to he largely in producing 
briliant sparks or fusing metals by means of a heavy 
current. Hare (3, 105, 1821) of the University of Penn- 
sylvania constructed a battery consisting of two troughs 
of forty cells each, so arranged that the coppers and 
zines can be lowered simultaneously into the acid and 
large currents obtained before polarization has a chance 
to interfere. This ‘‘deflagrator’’ was used to ignite 
charcoal in the circuit, or melt fine wires, and was for 
some time the most powerful arrangement of its kind. 
That ‘‘galvanism’’ is something quite different from 
static electricity was the opinion of many investigators ; 
Hare considered the heat developed to be the distinguish- 
ine mark of the electric current. He says: ‘‘It is 
admitted that the action of the galvanic fluid is upon or 
between atoms; while mechanical electricity when unco- 
erced, acts only upon masses. This difference has not 
been explained unless by my hypothesis, im which calorie, 
of which the influence is only exerted between atoms, 
is supposed to be a principal agent in galvanism.”’ 

Questioning minds were beginning to suspect that 
there must be some connection between electricity and 
magnetism. For lightning had been known to make 
magnets of steel knives and forks, and Franklin had mag- 
netized a sewing needle by the discharge from a Leyden 


L. Page—A Century’s Progress wm Physics. 3807 


jar. Finally Oersted of Copenhagen undertook syste- 
matic investigation of the effect of electricity on the mag- 
netic needle. His researches were without result until 
during the course of a series of lectures on ‘‘ Klectricity, 
Galvanism, and Magnetism’’ delivered during the winter 
of 1819-20 it occurred to him to investigate the action of 
an electric current on a magnetic needle. At first he 
placed the wire bearing the current at right angles to the 
needle, with,:of course, no result; then it occurred to 
him to place it parallel. A deflection was observed, for 
to his surprise the needle insisted on turning until per- 
pendicular to the wire. 

Oersted’s discovery that an electric current exerts a 
eouple on a magnetic needle was followed a few months 
later by Ampére’s demonstration before the French 
Academy that two currents flowing in the same direction 
attract each other, while two in opposite directions repel. 
The story goes that a critic attempted to belittle this dis- 
covery by remarking that as it was known that two cur- 
rents act on one and the same magnet, it was obvious 
that they would act upon each other. Whereupon Arago 
arose to defend his friend. Drawing two keys out of 
his pocket he said, ‘‘Kach of these keys attracts a mag- 
net; do you believe that they therefore attract each 
other?’’ 

A few years later Ampere showed how to express 
quantitatively the force between current elements, and 
indeed developed to a considerable degree the equiva- 
lence between a closed circuit carrying a current and a 
magnetic shell. So convincing was his analysis and so 
thorough his discussion of the subject, that Maxwell said 
of this memoir half a century later, ‘‘The whole, theory 
and experiment, seems as if it had leaped, full grown and 
full armed, from the brain of the ‘Newton of electricity.’ 
It is perfect in form and unassailable in accuracy; and 
it is summed up in a formula from which all the phe- 
nomena may be deduced, and which must always remain 
the cardinal formula of electrodynamics. ’’ 

Shortly afterwards the dependence of a current on the 
eonductivity of the wire used and the grouping of cells 
employed, was made clear by the work of Ohm. Many 
of his results were obtained independently by Joseph 
Henry (19, 400, 1831) of the Albany Academy, who 
described in 1831 a powerful electromagnet in which a 


308 LL. Page—A Century’s Progress in Physics. 
great many coils of wire insulated with silk were wound 
around an iron core and connected in parallel with a sin- 


gle cell. He remarks in this paper that with long wires, 


as in the telegraph, many cells arranged in series should 
be used, whereas for several short wires connected in 
parallel a single cell with large plates is more efficient. 

Current Induction.—Impressed by the fact that elec- 
tric charges have the power of inducing other charges 
on neighboring conductors without coming into contact 
with them, Faraday was engaged in investigating the 
possibility of an analogous phenomenon in the case of 
electric currents. His idea at first seems to have been 
that a current should induce another current in any 
closed conducting circuit which happens to be in its 
vicinity. Experiment readily showed the falsity of this 
conception, but a brief deflection of the galvanometer in 
the secondary circuit was noticed at the instant of mak- 
ing and breaking the current in the primary. Further 
experiments showed that thrusting a permanent steel 
magnet into a coil connected to a galvanometer caused 
the needle to deflect. In fact Faraday’s report to the 
Royal Society on November 24th, 1831, contains a com- 
plete account of all experimental methods available for 
inducing a current in a closed cireuit. 

While Faraday is entitled to credit for the discovery of 
current induction by virtue of the priority of his publica- 
tion, it must not pass unnoticed that Henry obtained 
many of the same experimental results independently 
and some even earlier. Henry was at this time instruc- 
tor in mathematics at the Albany Academy, and seven 
hours of teaching a day made it well-nigh impossible to 
carry on original research except during the vacation 
month of August. As early as the summer of 1830 he 
had wound 30 feet of copper wire around the armature 
of a horseshoe electromagnet and connected it to a gal- 
vanometer. When the magnet was excited, a momen- 
tary deflection was observed. ‘‘I was, however, much 
surprised,’’ he says, ‘‘to see the needle suddenly 
deflected from a state of rest to about 20° to the east, or 
in a contrary direction, when the battery was withdrawn 
from the acid, and again deflected to the west when 
it was re-immersed.’’ In addition a deflection was 
obtained by detaching the armature from the magnet, 
or by bringing it again into contact. Had the results of 


L. Page—A Century’s Progress in Physics. 309 


these experiments been published promptly, America 
would have been entitled to credit for the most important 
discovery of the greatest of England’s many great exper- 
imenters. But Henry desired first to repeat his 
experiments on a larger scale, and while new magnets 
were being constructed, the news of Faraday’s discovery 
arrived. This occasioned hasty publication of the work 
already done in an appendix to volume 22, 1832, of this 
Journal. 

At almost the same time Henry made another import- 
ant discovery and this time he was anticipated by no 
other investigator in making public his results. In the 
paper already referred to he describes the phenomenon 
known to-day as self-induction. ‘‘ When a small battery 
is moderately excited by diluted acid and its poles, which 
must be terminated by cups of mereury, are connected by 
a copper wire not more than a foot in length, no spark 
is perceived when the connection is either formed or 
broken; but if a wire thirty or forty feet long be used, 
instead of the short wire, though no spark will be per- 
ceptible when the connection is made, yet when it is 
broken by drawing one end of the wire from its cup of 
mercury a vivid spark is produced.... The effect 
appears somewhat increased by coiling the wire into a 
helix; it seems to depend in some measure on the length 
and thickness of the wire; I can account for these phe- 
nomena only by supposing the long wire to become 
charged with electricity which by its reaction on itself 
projects a spark when the connection is broken.’’ 

Soon after, Henry went to Princeton and there con- 
tinued his experiments in electromagnetism. No diffi- 
culty was experienced in inducing currents of the third, 
fourth and fifth orders by using the first secondary as 
primary for yet another secondary circuit, and so on 
(38, 209, 1840). The directions of these currents of 
higher orders when the primary is made or broken 
proved puzzling at first, but were satisfactorily explained 
a year later (41, 117, 1841). In addition induced cur- 
rents were obtained from a Leyden jar discharge. Fara- 
day failed to find any screening effect of a conducting 
eylinder placed around the primary and inside the 
secondary. Henry examined the matter, and found that 
the screening effect exists only when the induced current 
is due to a make or break of the primary circuit, and not 
when it is caused by motion of the primary. 


3810 L. Page—A Century’s Progress in Physics. 


Henry’s work was mainly descriptive; it remained for 
Faraday to develop a theory to account for the phenomena 
discovered and to prepare the way for quantitative for- 
mulation of the laws of current induction. This he did in 
his representation of a magnetic field by means of lines 
of force; a conception which he found afterwards to be 
equally valuable when applied to electrostatic problems. 
Every magnet and every current gives rise to these 
closed curves; in the case of a magnet they thread it 


from south pole to north, while a straight wire bearing 


a current is surrounded by concentric rings. The con- 
nection between lines of force and the induction of cur- 
rents is contained in the rule that a current is induced in 
a closed cireuit only when a change takes place in the 
number of lines of force passing through it. Further- 
more the dependence of the current strength on the 
conductivity of the wire employed has led to recognition 
of the fact that it is the electromotive force and not the 
current itself which is conditioned by the change in mag- 
netic flux. 

Great interest was attached to the utilization of the 
newly discovered forces of electromagnetism. In 1831 
Henry (20, 340, 1831) described a reciprocating engine 
depending on magnetic attraction and repulsion, and C. 
G. Page (33, 118, 1838; 49, 131, 1845) devised many 
others. The latter’s most important work, however, was 
the invention of the Ruhmkorff coil. In 1836 (31, 187, 
1837) he found the strongest shocks to be obtained from a 
secondary coil of many windings forming a continuation 
of a primary of half the number of turns. His perfec- 
tion of the self-acting circuit breaker (35, 252, 1839) 
widened the usefulness of the induction coil, and his sub- 
stitution of a bundle of iron wires for a solid iron core 
(34, 163, 1838) greatly increased its efficiency. 

Conservation of Energy.—FPerhaps the most important 
advance of the nineteenth century has been the estab- 
lishment of the principle of conservation of energy. 
Despite the fact that the ‘‘principe de la conservation des. 
force vives’’ had been recognized by the French mathe- 
maticians of the early part of the century, the application 
of this principle even to purely mechanical problems was 
contested by some scientists. Through the early num- 
bers of this Journal runs a lively controversy as to 
whether there is not a loss of power involved in impart- 


L. Page—A Century’s Progress in Physics. 311 


ing momentum to the reciprocating parts of a steam 
engine only to check the motion later on im the stroke. 
Finally Isaac Doolittle (14, 60, 1828), of the Bennington 
Tron Works, ends the discussion by the pertinent remark: 
‘‘Tf there be, as is contended by one of your correspond- 
ents, a loss of more than one third of the power, in trans- 
forming an alternating rectilinear movement into a 
continuous circular one by means of a crank, I should 
like to be informed what would be the effect if the propo- 
sition were reversed, as in the case of the common 
saw mill, and in many other instances in practical 
mechanics. ’’ 

A realization of the equivalence of heat and mechani- 
eal work did not come until the middle of the century, in 
spite of the conclusive experiments of the American 
Count Rumford and the English Davy before the year 
1800. So firmly enthroned was the ealoric theory, 
according to which heat is an indestructible fluid, that 
evidence against it was given scant consideration. In 
fact the success of the analytical method introduced by 
Fourier in 1822 for the solution of problems in conduc- 
tion of heat only added to the difficulties of the adherents 
of the kinetic theory. But recognition of heat as a form 
of energy was on the way, and when it came it made its 
appearance almost simultaneously in half a dozen differ- 
ent places. Perhaps Robert Mayer of Heilbronn was 
the first to state explicitly the new principle. His paper 
‘“‘On the Forces of Inorganic Nature’’ was refused 
publication in Poggendorff’s Annalen, but fared better at 
the hands of another editor. During the next few years 
Joule determined the mechanical equivalent of heat 
experimentally by a number of different methods, some 
of which had already been devised by Carnot. Of those 
he used, the most familiar consists in churning up a 
measured mass of water by means of paddles actuated by 
falling weights and calculating the heat developed from 
the rise in temperature. However, the work of the 
young ~“Manchester brewer received little attention from 
the members of the British Association before whom it 
was reported until Kelvin showed them. its significance 
and attracted their interest to it. Meanwhile Helmholtz 
had completed a very thorough disquisition on the con- 
servation of energy not only in dynamics and heat but in 
other departments of physics as well. His paper on 


312 L. Page—A Century’s Progress im Physics. 


‘‘Die Erhaltung der Kraft’’ was frowned upon by the 
members of the Physical Society of Berlin before whom 
he read it, and received the same treatment as Mayer’s 
from the editor of Poggendorff’s Annalen. Helmholtz’s 
‘‘Kraft,’’ like the ‘‘vis viva’’ of other writers, is the 
quantity which Young had already christened energy. 
Not many years elapsed, however, until the convictions of 
Mayer, Joule, Kelvin and Helmholtz became the most 
clearly recognized of all physical principles. As early 
as 1850 Jeremiah Day (10, 174, 1850), late president of 
Yale College, admitted the improbability of constructing 
a machine capable of perpetual motion, even though the 
‘‘ymponderable agents’’ of electricity, galvanism and 
magnetism be utilized. 

Thermodynanucs.—The importance of the principle of 
conservation of energy lies in the fact that it unites under 
one rule such diverse phenomena as gravitation, electro- 
magnetism, heat and chemical action. Another principle 
as universal in its scope, although depending upon the 
coarseness of human observations for its validity rather 
than upon the immutable laws of nature, was fore- 
shadowed even before the first law of thermodynamics, 
or principle of conservation of energy, was clearly 
recognized. This second law was the consequence of 
efforts to improve the efficiency of heat engines. In 1824 
Carnot introduced the conception of cyclic operations 
into the theory of such engines. Assuming the impos- 
sibility of perpetual motion, he showed that no engine can 
have an efficiency greater than that of a reversible 
engine. Finally Clausius expressed concisely the princi- 
ple toward which Carnot’s work had been leading, when 
he asserted that ‘‘it is impossible for a_ self-acting 
machine, unaided by any external agency, to convey heat 
from one body to another at a higher temperature.’’ 
Kelvin’s formulation of the same law states that ‘‘it is 
impossible, by means of inanimate material agency, to 
derive mechanical effect from any portion of matter by 
cooling it below the temperature of the coldest of the 
surrounding objects. ’’ 

The consequences of the second law were rapidly 
developed by Kelvin, Clausius, Rankine, Barnard (16, 
218, 1853, et seq.) and others. Kelvin introduced the 
thermodynamic scale of temperature, which he showed 
to be independent of such properties of matter as con- 


L. Page—A Century’s Progress in Physics. 318 


dition the size of the degree indicated by the mercury 
thermometer. ‘This scale, which is equivalent to that of 
the ideal gas thermometer, was used subsequently by 
Rowland in his exhaustive determination of the mechan- 
ical equivalent of heat by an improved form of Joule’s 
method. He found different values for different ranges 
in temperature, showing that the specific heat of water 
is by no means constant. Since then electrical methods 
of measuring this important quantity have been used to 
confirm the results of purely mechanical determinations. 

The definition of a new quantity, entropy, was found 
necessary for a mathematical formulation of the second 
law of thermodynamics. This quantity, which acts as a 
measure of the unavailability of heat energy, was given 
a new significance when Boltzmann showed its connec- 
tion with the probability of the thermodynamic state of 
the substance under consideration. If two bodies have 
widely different temperatures, a large amount of the 
heat energy of the system is available for conversion 
into mechanical work. From the macroscopic point of 
view this is expressed by saying that the entropy is small, 
or if the motions of the individual molecules are taken 
into account, the probability of the state is low. The 
interpretation of entropy as the logarithm of the thermo- 
dynamic probability has thrown much light on the 
meaning of this rather abstruse quantity. Gibbs’s 
‘‘Hilementary Principles in Statistical Mechanics’’ treats 
in detail the fundamental assumptions involved in 
this point of view, its limitations and its consequences. 
In his ‘‘Equilibrium of Heterogeneous Substances’’” 
he had already extended the principle of thermal equi- 
hbrinm to include substances which are no longer homo- 
geneous. The value of the chemical potential he intro- 
duced determines whether one phase is to gain at the 
expense of another or lose to it. It is unfortunate that 
the analytical rigor and austerity of his reasoning com- 
bined with lack of mathematical training on the part of 
the average chemist, delayed true appreciation of his 
work and full utilization of the new field which he 
opened up. 

LIiquefaction of Gases—Meanwhile the problem of 
hquefying gases was attracting much attention on the 


1 J. W. Gibbs, Trans. Conn. Acad. Arts and Sci., 3, 108 and 343. Abstract 
by the author, this Journal, 16, 441, 1878. 


——SSS—> 


314 L. Page—A Century’s Progress im Physics. 


part of experimental physicists. Faraday had succeeded 
in making liquid a number of substances which had 
hitherto been known only in the gaseous state. His 
method consists in evolving the gas from chemicals 
placed in one end of a bent tube, the other end of which 
is immersed in a freezing mixture. The high pressure 
caused by the production of the gas combined with the 
low temperature is sufficient to bring about liquefaction 
in many cases. Failure with other more permanent 
gases was unexplained until the researches of Andrews 
in 1863 showed that no amount of pressure will produce 
liquefaction unless the temperature is below a certain 
eritical value. The method of reducing the temperature 
in use to-day depends on a fact discovered by Kelvin and 
Joule in connection with the free expansion of a gas. 
These investigators allowed the gas to escape through a 
porous plug from a chamber in which the pressure was 
relatively high. With the single exception of hydrogen, 
the effect of the sudden expansion is to cool the gas, and 
even with it cooling is found to take place after the tem- 
perature has been made sufficiently low. By this method 
all known gases have been liquefied. Helium, with a 
boiling point of —269°C., or onlv 4°C. above the absolute 
zero, was the last to be made a liquid, finally yielding to 
the efforts of Kammerlingh Onnes in 1907. This inves- 
tigator? finds that at temperatures near the absolute zero 
the electrical conductivity of certain substances undergoes 
a profound modification. For example, a coil of lead 
shows a superconductivity so great that a current once 
started in it persists for days after the electromotive 
force has ceased to act. 

Electrodynamics.—Faraday’s representation of elec- 
tric and magnetic fields by lines of force had been of 
oreat value in predicting the results of experiments in 
electromagnetism. But a more mathematical formula- 
tion of the laws governing these phenomena was needed 
in order to make possible quantitative development of 
the theory. This was supplied by Maxwell in his 
epoch-making treatise on ‘‘Electricity and Mag- 
netism.’’ Starting with electrostatics and magnetism, 
he gives a complete account of the mathematical 
methods which had been devised for the solution 
of problems in these branches of the subject, and 

?H. K. Onnes, Nature, 93, 481, 1914. ‘ 


L. Page—A Century’s Progress in Physics. 315 


then turning to Ampére’s work he shows how the 
Lagrangian equations of motion lead to Faraday’s law 
if the single assumption is made that the magnetic 
energy of the field is kinetic. In the treatment of open 
circuits Maxwell’s intuition led to a great advance, the 
introduction of the displacement current. Consider a 
charged condenser, the plates of which are suddenly con- 
nected by a wire. A current will flow through the wire 
from the positively charged plate to the negative, but in 
the gap between the two plates the conduction current 
is missing. So convinced was Maxwell that currents 
must always flow in closed circuits, that he postulated an 
electrical displacement in the medium between the plates 
of a charged condenser, which disappears when the con- 
denser is short-circuited. Thus even in the so-called 
open circuit the current flows along a closed path. 
Maxwell’s theory of the electromagnetic field is based 
essentially on Faraday’s representation by lines of force 
of the strains and stresses of a universal medium. So it 
is not surprising that he was led to a consideration of 
the propagation of waves through this medium. The 
introduction of the displacement current made the form 
of the electrodynamic equations such as to yield a typical 
wave equation for space free from electrical charges and 
eurrents. Moreover, the disturbance was found to be 
transverse, and its velocity turned out to be identical 
with that of light. The conclusion was _ irresistible. 
That light could consist of anything but electromagnetic 
waves of extremely short length was inconceivable. In 
fact so certain was Maxwell of this deduction from 
theory that he felt it altogether unnecessary to resort to 
the test of experiment. For the electromagnetic theory 
explained so many of the details which had been revealed 
by experiments in light, that no doubt of its validity 
could be entertained. Even dispersion received ready 
elucidation on the assumption that the dispersing 
medium is made up of vibrators having a natural period 
comparable with that of the hght passing through it. 
Maxwell’s book was published in 1873. Fifteen years 
later, Hertz,*? at the instigation of Helmholtz, succeeded 
in detecting experimentally the electromagnetic waves 
predicted by Maxwell’s theory. His oscillator consisted 
of two sheets of metal in the same plane, to each of which 
7H. Hertz, Wied. Ann., 34, 551, 1888 et seq. 


3816 L. Page—A Century’s Progress m Physics. 


was attached a short wire terminating in a knob. The 
knobs were placed within a short distance of each other, 
and connected to the terminals of an induction coil. By 
reflection standing waves were formed, and the positions 
of nodes and loops determined by a detector composed of 
a movable loop of wire containing an air gap. Thus the 
wave length was measured. Hertz calculated the fre- 
quency of his radiator from its dimensions, and then 
computed the velocity of the disturbance. In spite of an 
error in his calculations, later pointed out by Poincaré, 
he obtained very nearly the velocity of light for waves 
traveling through air, but a velocity considerably smaller 
for those propagated along wires. Subsequent work by 
Lecher, Sarasin and de la Rive, and Trowbridge and 
Duane (49, 297, 1895; 50, 104, 1895) cleared up this dis- 
crepancy, and showed the velocity to be in both eases 
identical with that of light. The last-named investiga- 
tors increased the size of the oscillator until it was possi- 
ble to measure the frequency by photographing the spark 
in the secondary with a rotating mirror. The positions 
of nodes and loops were obtained by means of a bolom- 
eter after the secondary had been tuned to resonance 
with the vibrator. The velocity thus found for electro- 
magnetic waves along wires is within one-tenth of one 
percent of the accepted value of the velocity of hght. 
Hertz’s later experiments showed that waves in air suf- 
fer refraction and diffraction, and he succeeded in 
polarizing the radiation by passing it through a grating 
constructed of parallel metallic wires. 

In order to satisfy the law of action and reaction, it 
is found necessary to attribute a quasi-momentum to 
electromagnetic waves. When a train of such waves is 
absorbed, their momentum is transferred to the absorb- 
ing body, while if they are reflected an impulse twice as 
great is imparted. This consequence of theory, foreseen 
by Maxwell and developed in detail by Poynting, Abra- 
ham and Larmor, has been verified by the experiments of 
Lebedew, and Nichols and Hull.t The latter used a deli- 
cate torsion balance from which was suspended a couple 
of silvered glass vanes. In order to eliminate the effect 
of impulses imparted by the molecules of the residual 
gas, such as Crookes had observed in his radiometer, 
readings were made at many different pressures and the 

“HK. F. Nichols and G. F. Hull, Phys. Rev., 13, 307, 1901 et seq- 


L. Page—A Century’s Progress in Physics. 317 


ballistic rather than the static deflection recorded. 
After the pressure produced by hght from a carbon arc 
had been measured, the intensity of the radiation was 
determined with a bolometer. Preliminary experiments 
indicated the existence of a pressure of the order 
expected, and later more careful measurements showed 
good quantitative agreement with theory. This pressure 
had already found an important application in Lebedew’s 
explanation of the solar repulsion of comet’s tails. 
These tails are made up of enormous swarms of very 
minute particles, and as the comet swings around the 
sun they suffer a repulsion due to the pressure of the 
intense solar radiation which counteracts the sun’s gravi- 
tational attraction. Hence the tail, instead of following 
after the comet in its orbit, points in a direction away 
from the sun. 

Some uncertainty existed as to whether a convection 
current produces a magnetic field. A compass needle 
is deflected by a current from a Daniell cell; is the same 
effect obtained when a conductor is charged electro- 
statically and then whirled around the needle by means 
of an insulating handle? The experimental difficulties 
involved in settling this question are realized when the 
enormous difference between the electrostatic and elec- 
tromagnetic units of current is taken into consideration. 
For a sphere one centimeter in radius, charged to a 
potential of 20,000 volts, and revolving in a circle sixty 
times a second, constitutes a current of little over a 
millionth of an ampere. 

This problem was undertaken by Rowland (15, 30, 
1878) in Helmholtz’s laboratory at Berlin in 1876. A 
hard rubber disk coated on both sides with gold was 
charged and rotated about a vertical axis at a rate of 
sixty revolutions a second. On reversing the sign of the 
electrification on the disk, the astatic needle hung above 
its center showed a deflection of over five millimeters. 
The current was calculated in electrostatic units from the 
charge on the disk and its rate of motion, and in electro- 
magnetic units from the magnetic deflection. The ratio 
of these two quantities gave fair agreement with its theo- 
retical value, the velocity of light. 

Although the result of this experiment was confirmed 
by Rowland and Hutchinson in 1889, Crémieu was con- 
vineed by an investigation carried out at Paris in 1900 


318 LL. Page—A Century’s Progress in Physics. 


that the Rowland effect did not exist. Consequently 
further repetition of the experiment was desirable. So 
the following year Adams (12, 155, 1901) arranged two 
rings of eight spheres each so that they could be rotated 
about their common axis from fifty to sixty times a sec- 
ond. One set of spheres was connected by brushes to the 
positive pole of a battery of 20,000 volts, the other to the 
negative pole. The deflection of a nearby magnetometer 
needle was observed when the electrification of the two 
rings was reversed, and from the reading so obtained the 

ratio of the electromagnetic to the electrostatic unit of 
current computed. This quantity was found to differ 
from the velocity of light by only a few percent. This 
experiment and the even more exhaustive investigations 
earried out by Pender, both independently and in collab- 
oration with Crémieu, finally convinced the scientific 
world that a convection current produces the same mag- 
netic field as a conduction current of the same magnitude. 

In discussing the ponderomotive force experienced in a 
magnetic field by a conductor through which a current is 
passing, Maxwell had said, ‘‘It must be carefully remem- 
bered, that the mechanical force which urges a conductor 
carrying a current across the lines of magnetic force, 
acts, not on the electric current, but on the conductor 
which earries it.’’ Hall (19, 200, 1880), one of Row- 
land’s students, questioned this statement, and deter- 
mined to put it to the test of experiment. Efforts to find 
an increase in the resistance of a wire placed at right 
angles to the lines of magnetic force were unsuccessful. 
So the current was passed through a moderately broad 
strip of gold leaf and the effect of the magnetic field 
on the equipotential lines investigated. The results | 
obtained confirmed Hall’s belief that the force exerted by 
the field acts on the current itself, and is transmitted 
through it to the conductor. Further investigation (20, 
161, 1880) revealed the same deflection of equipotential 
lines in thin strips of other metals, although the effect 
was found to be reversed in iron. 

During the closing years of the fev eent century 
occurred three events of far reaching importance. The 
electron was isolated, and its charge and mass measured 
by J. J. Thomson in England; X-rays were discovered 
by Rontgen in Germany; and the first indications of 
radioactivity were found by Becquerel in France. ‘The 


L. Page—A Century’s Progress in Physics. 319 


first two are certainly to be attributed largely to the 
ereat advances which had been made in obtaining high 
vacua, and the last two might not have occurred so soon 
had it not been for the photographic plate. 

The Electron.—The atomic theory of electricity dates 
from the time of Faraday. His experiments on electroly- 
sis Showed that each monovalent atom or radical, what- 
ever its nature, carries the same charge, each bivalent ion 
a charge twice as great. Only a lack of knowledge of the 
number of atoms in a gram of the dissociated salt pre- 
vented him from calculating the value of the elementary 
charge. As the discharge of electricity through gases at 
low pressures became a subject for experimental inves- 
tigation, another line of approach to the study of the 
atom of electricity was opened up. As early as the sev- 
enties Hittorf and Goldstein had observed that a shadow 
is east by a screen placed in front of the cathode of a 
Crookes tube. Varley suggested that the cathode rays 
producing the shadow consist of ‘‘attenuated particles of 
matter, projected from the negative pole by electricity.’’ 
The discovery that these rays are deflected by a magnetic 
- field led English physicists to the conclusion that they 
must be composed of charged particles, and the direction 
of the deflection was such as to require the charge to be 
negative. Hertz contested this view on the ground that 
his experiments showed the rays to be unaffected by an 
electrostatic field, and suggested that they consist of 
etherial disturbances. Finally Perrin succeeded in pass- 
ing the rays into a metal cylinder which received from . 
them a negative charge, and Lenard showed how exces- 
sively minute these negatively charged particles must be 
by actually passing them through a thin sheet of alumi- 
nium in the wall of a vacuum tube, and detecting their 
presence in the air outside. Conclusive information as 
to the nature of the electron, as it was named by John- 
stone Stoney, was supplied by the classic experiments 
of J. J. Thomson.’ First he showed that Hertz’s failure 
to find a deflection when a stream of electrons passes 
between the plates of a charged condenser was due to the 
sereening effect of the gaseous ions produced by the dis- 
charge. With a much more highly evacuated tube he 
found no difficulty in obtaining a deflection in an electro- 
static field. By using crossed electric and magnetic 

°J. J. Thomson, Phil. Mag., 44, 293, 1897. 


3820 LL. Page—A Century’s Progress in Physics. 


fields the deflection produced by one was just balanced by 
that caused by the other, and from the field strengths 
employed both the velocity of the particles and the ratio 

é 


,, OL charge to mass was calculated. The former was 


found to be about one-tenth the velocity of light, but the 
most startling result of the experiment was that the same 


é é : 
value of —- was obtained no matter what residual gas 


was contained in the tube or of what metal the cathode 
was made. | 

To calculate e and then m other methods are necessary. 
C. T. R. Wilson has shown that in supersaturated air, 
water drops form easily on charged molecules, and that 
negative ions are more effective in causing condensation 
than positive ones. By making use of the results of this 
research Thomson has been able to measure the elemen- 
tary charge. For suppose a stream of negative ions to 
pass through supersaturated air. A little drop forms 
on each charged particle, and the cloud of condensed 
vapor settles to the bottom of the vessel. The charge 
carried and the mass of water deposited can: be meas- 
ured directly. Stokes’ law for the rate of fall of a 
minute particle through a gaseous medium enables the 
average size of the drops to be computed from the 
observed rate of descent of the cloud. Hence the number 
of drops formed and the charge carried by each follows 
at once. H. A. Wilson improved the method by noting 
the effect of an electric field upon the rate of fall of the 
charged drops, and subsequent experiments undertaken 
by Millikan® have been of such a character as to enable 
him to follow the motion of a single drop. Instead of 
water, the latter uses oil drops less than one ten- 
thousandth of a centimeter in diameter. <A drop, after 
one or more electrons have attached themselves to it, 
is actually weighed in terms of the charge on its surface 
by applying an upward electric force just sufficient to 
balance the force of gravity. Then its weight is inde- 
pendently obtained from the density of the oil and the 
radius of the drop as determined by the rate of fall when 
the electric field is absent. Comparison of these two 
expressions gives 4:774(10)7° electrostatic units for the 

°R. A. Millikan, Phys. Rev., 2, 109, 1913. 


L. Page—A Century’s Progress in Physics. 821 


elementary charge. Combining this result with the 
value of ~ found by Thomson, the mass of the electron 


comes out to be about one eighteen-hundredth that of an 
atom of the lightest known element, hydrogen. 

That the electron is a fundamental constituent of all 
matter is attested by the fact that charge and mass are 
the same regardless of the source or manner of produc- 
tion. Whether emitted by a heated metal, under the 
action of ultra-violet ight, from a radioactive substance, 
by a body exposed to X-rays, as a result of friction, it is 
the same negatively charged particle that constitutes the 
cathode ray of the discharge tube. Moreover, it makes 
its effect felt indirectly in many other phenomena, and 
from an investigation of some of these the ratio of 
charge to mass, can be determined independently. Of 
such perhaps the most interesting is the Zeeman effect. 

Spectroscopy.—Harly in the nineteenth century Fraun- 
hofer had observed that the solar spectrum is crossed 
by a large number of dark lines. Their presence was 
unexplained until in 1859 Kirchhoff and Bunsen showed 
‘‘that a colored flame, the spectrum of which contains 
bright sharp lines, so weakens rays of the color of these 
lines when they pass through it, that dark lines appear 
in place of bright lines as soon as there is placed behind 
the flame a light of sufficient intensity, in which the lines 
are otherwise absent.’’ For intra-atomic oscillators 
must have the natural frequency of the radiation which 
they emit, and consequently resonance will take place 
when they are exposed to rays of this frequency coming 
from an outside source, and selective absorption ensue. 
By comparing the bright lines in the spectra of metallic 
vapors made luminous by a gas flame with the dark lines 
in the sun’s spectrum these investigators showed that 
many of the common terrestrial elements exist in the 
sun. The interest in spectroscopy grew rapidly. The 
excellent diffraction gratings made by Rutherfurd were 
succeeded by the superior concave gratings of Rowland. 
In 1877 Draper (14, 89, 1877) announced the discovery of 
the bright lines of oxygen in the solar spectrum, but his 
interpretation of his photographs has not been corrob- 
orated by the work of later investigators. Langley (11, 
401, 1901), by the aid of his newly invented bolometer, 
succeeded in detecting the emission of energy from the 


Am. Jour. Sct —Fourts Srrtizs, Vout. XLVI, No. 271.—Juty, 1918. 
1 ‘ 


322 LL. Page—A Century’s Progress in Physics. 


sun in the infra-red in amounts far exceeding that con- 
tained in the visible spectrum. In 1842 Doppler drew 
attention to the fact that motion of the source should 
cause a displacement of the spectral lines, the shift being 
to the blue if the light is approaching and to the red if 
it is receding, and a few years later Fizeau suggested the 
appheation of Doppler’s principle to the measurement of 
the velocity of a star moving in the line of sight. Thus 
the spectroscope has been able to supply one of the 
deficiencies of the telescope, and the two together are 
sufficient to reveal all components of stellar motion. 
When spectra formed by hight from the sun’s limb and 
from its center are compared, the same effect reveals 
the rotation of the sun about its axis. (C. 8. Hastings, 5, 
SOD aleios iC. Ac Woune a2 o24-) 1 S76) 

Further Evidence of the Electron.—In 1845 Faraday 
discovered a rotation of the plane of polarization when 
light passes in the direction of the lines of force through 
a piece of glass placed between the poles of an electro- 
magnet. Hxamination of the spectrum from a glowing 
vapor situated between the poles of a magnet, however, 
failed to reveal any effect of the field. The latter prob- 
lem was attacked anew by Zeeman’ in 1896, and with the 
aid of the improved appliances of modern science he suc- 
ceeded in detecting a broadening of the lines. Later 
experiments with more powerful apparatus resolved 
these broadening lines into several components. 

Lorentz® showed at once how the electron theory fur- 
nishes an explanation of the Zeeman effect. He found 
that when the source is viewed at right angles to the lines 
of magnetic force, a spectral line should be split into 
three components. Of these he predicted that the mid- 
dle, or undisplaced component, would be found to be 
polarized at right angles to the direction of the field, and 
the other components parallel to the field. When the 
light proceeds from the source in a direction parallel to 
the magnetic lines of force, two components only should 
be formed, and these should be circularly polarized in 
opposite senses. Moreover, from the separation of the 
components can be calculated the ratio of charge to mass 
of the electronic vibrator which is responsible for the 
emission of radiant energy. Zeeman’s experiments con- 


7™P. Zeeman, Phil. Mag., 43, 226, 1897. 
8H. A. Lorentz, Phil. Mag:, 43, 232, 1897. 


L. Page—A Century’s Progress in Physics. 323 


firmed Lorentz’s theory in every detail, and yielded a 
value of = in substantial agreement with that obtained 


for cathode rays. Subsequent research, however, has 
shown that in many cases more components are found 
than the elementary theory calls for. Hale has detected 
the Zeeman effect in light from sun spots, proving that 
these blemishes on the sun’s face are vortices caused by 
whirling swarms of electrified particles. Recently Stark 
and Lo Surdo have found a similar splitting up of lines 
in the spectrum formed by light from canal rays (rays of 
positively charged particles) passing through an intense 
electric field. This phenomenon has as yet received no 
adequate explanation. 

On discovering that an electric current is capable of 
producing a magnetic field, Ampére had suggested that 
the magnetic properties of such substances as iron might 
be explained on the assumption of molecular currents. 
The electron theory considers these currents to be due to 
the revolution, inside the atom, of negatively charged 
particles about an attracting nucleus. It occurred to 
Richardson that this motion should give the atom the 
properties of a gyrostat. Hence if an iron bar be rotated 
about its axis, the atoms should orient themselves so as to 
make their axes more nearly parallel to the axis of rota- 
tion. Thus its rotation should cause the bar to become 
a magnet. Barnett® has tested this hypothesis, and has 
found the effect Richardson had predicted. From the 


strength of the magnetization produced, the value of 


can be computed. Barnett finds a value somewhat 
smaller than that for cathode rays, but of the right order 
of magnitude and sign. Einstein and De Haas have 
detected the inverse of this effect, i. e., the rotation of an 
iron rod when it is suddenly magnetized. 

X-Rays—In 1895, on developing a plate which had 
been lying near a vacuum tube, Rontgen!® was surprised 
to find distinct markings on it. As the plate had never 
been exposed to light, it was necessary to suppose the 
effect to be due to some new and unknown type of radia- 
tion. Further investigation showed that this radiation 
originates at the points where cathode rays impinge on 


°S. J. Barnett, Phys. Rev., 6, 239, 1915, and 10, 7, 1917. 
*”'W. C. Rontgen, Wied. Ann., 64, 1, 1898 et seq. 


324 LL. Page—A Century’s Progress mm Physics. 


the glass walls of the tube. Besides being able to pass 
with ease through all but the most dense material objects 
X-rays were found to have the power of ionizing gases 
through which they pass and ejecting electrons from metal 
surfaces against which they strike. The poimts at which 


these electrons are produced are in turn the sources of 


secondary X-rays whose properties are characteristic of 
the metal from which they come. 

Rontgen’s discovery excited intense interest among 
laymen as well as in scientific cireles. Of the many 
X-ray photographs taken, those of Wright (1, 235, 1896) 
of Yale were the first to be produced in this country. 
His experiments were made immediately on receipt of 
the news of Rontgen’s research, and resulted in the pub- 
lication of a number of photographs showing the trans- 
lucency for these rays of paper, wood, and even 
aluminium. 

As X-rays are undeviated by electric or magnetic fields, 
Schuster, and later Wiechert and Stokes, suggested that 
they might be electromagnetic waves of the same nature 
as light, but much shorter and less regular. The great 
objection to this hypothesis was the failure either to 
refract or diffract these rays. In fact Bragg contended 
that they were not etherial disturbances at all, but con- 
sisted of neutral particles moving with very high veloci- 
ties. Finally Lanett demonstrated their undulatory’ 
nature by showing that diffraction took place under 
proper conditions. Just as the distance between adja- 
cent lines of a grating must be comparable to the wave 
length of light for a spectrum to be formed, a periodic 
structure with a grating space of their very much shorter 
wave length is necessary to diffract X-rays. Such a 
structure is altogether too fine to be made by human 
tools. Nature, however, has already prepared it for 
man’s use. The distance between the atoms of a crystal 
is just right to make it an excellent X-ray grating, and 
Laue had no difficulty in obtaining diffraction patterns 
when Rontgen rays were passed through a block of zine- 
blende. The distance between adjacent atoms of this 
cubic crystal can be computed at once from its density 
and molecular weight, and then the wave length of the 
radiation calculated from the deviation suffered. In this 
way X-rays are found to have a length less than one 

u W. Friedrich, P. Knipping, and M. Laue, Ann. d. Phys., 41, 971, 1913. 


L. Page—A Century’s Progress wm Physics. 325 


thousandth as great as visible light. Further study of 
this phenomenon, particularly by the two Bragegs, father 
and son, has revealed many of the structural details of 
more complicated crystals. 

The most significant investigation in the field opened 
up by Laue’s discovery is that undertaken by Moseley” 
only a couple of years before he lost his life in the 
trenches at Gallipoli. Using many different metals as 
anticathodes in a vacuum tube, he measured the fre- 
quencies of the characteristic rays emitted. He found 
that if the elements are arranged in order of increasing 
atomic weight, the square roots of the characteristic fre- 
quencies form an arithmetical progression. If to each 
element is assigned an integer, beginning with one for 
hydrogen, two for helium, and so on, the square root of 
the frequency of the characteristic radiation is found to 
be proportional to this atomic number. Even though 
Uhler has shown recently that over wide ranges Mose- 
ley’s law does not hold within the limits of experimental 
error, there is undoubtedly much significance to be 
attached to this simple relation. 

Radioactivity —The year following the discovery of 
X-rays, Becquerel found that a photographic plate 
is similarly affected by radiations from uranium 
salts. Two years later the Curies separated from 
pitechblende the very active elements polonium and 
radium. Passage of the rays from these substances 
through electric and magnetic fields revealed the 
existence of three types. The alpha rays have 
been shown by Rutherford and his co-workers to be 
positively charged helium atoms; the beta rays are very 
rapidly moving electrons; and the gamma rays are elec- 
tromagnetic pulses of the same nature as X-rays but 
somewhat shorter. In 1902 Rutherford and Soddy 
advanced the theory of atomic disintegration, according 
to which the emission of a ray is an indication of the 
breaking down of the atom to a simpler form. Thus in 
the radioactive substances there is going on before our 
eyes a continual transformation of one element into 
another, a change, by the way, which appears to be in no 
slightest degree either hastened or delayed by changes in 
temperature (H. L. Bronson, 20, 60, 1905) or external 
electrical condition of the radioactive element. Uranium 

YH. G. J. Moseley, Phil. Mag., 26, 1024, 1913, and 27, 703, 1914. 


ii 


326 DL. Page—A Century’s Progress wm Physics. 


is the progenitor of a long line of descendants, of which 
radium was supposed for some time to be the first mem- 
ber. Boltwood (25, 365, 1908) of Yale, however, showed 
that the slow growth of radium in uranium solutions is 
incompatible with this assumption, and soon isolated an 
intermediate product which he named ionium. Radium 
itself disintegrates into a gas known as radium emana- 
tion, which in turn gives rise to a succession of other 
products. Analyses by Boltwood (23, 77, 1907) of radio- 
active minerals from the same locality show such a con- 
stant ratio between the amounts of uranium and lead 
present that it is natural to conclude that lead is the end 
product of the series. This hypothesis is confirmed by 
the fact that the oldest rocks show relatively the greatest 
amounts of this element. 

In addition to the Ionium-Radium series two others 
have been discovered. Of these Boltwood’s (25, 269, 1908) 
investigations seem to indicate that the one which starts 
with actinium is a collateral branch of the radium series 
and comes from the same parent uranium. The other 
begins with thorium and comprises ten members. As 
yet the end products of the actinium and thorium series 
have not been identified, although there is some reason 
for believing that an isotope of lead may be the final 
member of the latter. 

As the amount of a radioactive element which disin- 
tegrates in a given time is proportional to the total mass 
present, an infinite time would be required for the sub- 
stance to be completely transformed. Hence the life of 
such an element is measured by the half value period, or 
time taken for half the initial mass to disintegrate. 
This time varies widely for different radioactive sub- 
stances, ranging from a small fraction of a second for 
actinium <A to five billion years for uranium. Bolt- 
wood’s (25, 493, 1908) original determination of the life 
of radium from the rate of its growth in a solution con- 
taining ionium gave 2000 years as its result, although 
recent measurements by Miss Gleditsch (41, 112, 1916) 
agree more closely with the value 1760 years obtained by 
Rutherford and Geiger from the number of alpha parti- 
cles emitted. 

Under the action of X-rays or the radiations from 
radioactive substances, gases acquire a conductivity 
which has been attributed by Thomson and Rutherford 


L. Page—A Century’s Progress in Physics. 327 


to the formation of ions. Zeleny has found that ions of 
opposite sign have somewhat different mobilities in an 
electric field, and experiments of Wellisch (39, 583, 1915) 
show that at low pressures some of the negative ions are 
electrons. T.S. Taylor (26, 169, 1908 et seq.) and Duane 
(26, 464, 1908) have investigated the ionization produced 
by alpha particles, and Bumstead (32, 403, 1911 et seq.) 
has studied the emission of electrons from metals which 
are bombarded by these rays. The investigations of 
Franck and Hertz, and McLennan and Henderson, show 
a significant relation between the ionizing potential 
(energy which must be possessed by an electron in order 
to produce an ion on colliding with an atom) and a quan- 
tity, to be considered later in more detail. which has been 
introduced by Planck into the theory of radiation. 
Methods of Scvence.—Scientific progress seems to fol- 
low a more or less clearly defined path. Experimenta- 
tion brings to light the hidden processes of nature, and 
hypotheses are advanced to correlate the facts discov- 
ered. As more and more phenomena are found to fit into 
the same scheme, the hypotheses at first proposed tenta- 
tively, although often only after extensive alterations, 
become firmly established as theories. Finally there may 
appear a fundamental clash between two theories, each of 
which in its respective domain seems to represent the only 
possible manner in which a large group of phenomena 
can be correlated. The maze becomes more perplexing 
at every step. At last a genius appears on the scene, 
approaches the problem from a new and unsuspected 
point of view, and the paradox vanishes. Such changes 
in point of view are the milestones which mark the 
progress of science. That science is stagnant whose 
only function is to collect, classify and correlate vast 
stores of experimental data. The sign of vitality is the 
existence of clearly defined and fundamental problems 
any possible solution of which seems irreconcilable with 
the most basic truths of the science in question. The 
greater the paradox grows, the more certain the advent 
of a new point of view which will bring one step nearer 
the comprehensive picture of nature which is the goal of 
natural philosophy. | 
The Ether —F rom the earliest times philosophers have 
been attracted by the possibility of explaining physical 
phenomena in terms of an all-pervading medium. So 


328 L. Page—A Century’s Progress in Physics. ; 


strong had this tendency become by the middle of the 
nineteenth century that the English school of physicists 
were attributing rigidity, density and nearly all the prop- 
erties of material media to the ether. In fact most 
physicists seemed to have forgotten that no experiment 
had ever given direct evidence of the existence of such a 
medium. Not until the first decade of the twentieth cen- 
tury was it realized that the experimental evidence actu- 
ally pointed in quite the opposite direction, and that a 
new point of view was needed in dealing with those phe- 
nomena of lght and electromagnetism which had been 
previously described in terms of a universal medium. 
Some account of the development of the ether theory 
and of the origin and growth of the point of view which 
has its principal exemplification in the principle of rela- 
tivity is essential for an understanding of present ten- 
dencies in formulating a philosophic basis for scientific 
thought. ; 
In the time of Newton and for a century after there was 
much controversy between the adherents of two irrecon- 


cilable theories of light. Hooke had suggested that 


light is a wave motion traveling through a homogeneous 
medium which fills all space, and Huygens had shown 
that the law of refraction can be deduced at once from 
this hypothesis if it is assumed that the velocity of light 
in a transparent body is less than that in free ether. 
However, Newton, impressed by the fact that a ray 
obtained by double refraction in Iceland spar differs from 
a ray of ordinary light just as a rod of rectangular cross 
section differs from one of circular cross section, and 
seeing no wav of explaining this dissymmetry in terms 
of a wave motion analogous to longitudinal sound waves, 
adhered to the view that light consists of infinitesimal 
particles shot out from the luminous body with enormous 
velocities. So great was his reputation on account of his 
discoveries in other fields that this theory of hght held 
sway among his contemporaries and successors until the 
labors of Young and Fresnel at the beginning of the 
nineteenth century definitely established the undulatory 
theory. However, in spite of the fact that a corpuscular 
theory of hght made the assumption of an ether unneces- 
sary in so far as the simpler of the observed phenomena 
are concerned, even Newton postulated the existence of 
such a medium, partly in order to explain the more com- 


L. Page—A Century’s Progress in Physics. 329 


plicated results of experiments in light, and partly in 
order to provide a vehicle for the propagation of gravi- 
tational forces. 3 

Now an ether, if it is to explain anything at all, must 
have at least some of the simpler properties of material 
media. The most fundamental of these, perhaps, is posi- 
tion in space. As a first approximation in explaining 
optical phenomena on the earth’s surface, the earth 
might be supposed to be at rest relative to the ether. 
But the establishment of the Copernican system made the 
sun the center of the solar system and gave the earth an 
orbital speed of eighteen miles a second. It may be 
remarked parenthetically that the speed of a point on the 
equator due to the earth’s diurnal rotation is quite insig- 
nificant compared to its orbital velocity. Hence as a 
second approximation the sun might be considered at 
rest relative to the ether and the earth as moving 
through this unresisting medium. 

The first indication of this motion lay in the discovery 
of aberration by the British astronomer Bradley in 1728. 
Bradley noticed that stars near the pole of the ecliptic 
describe small circles during the course of a year, while 
those in the plane of the ecliptic vibrate back and forth 
in straight lines, stars in intermediate positions describ- 
ing ellipses. The surprising thing, however, was that 
the time taken to complete one of these small orbits is in 
all eases exactly a year. Bradley concluded that the 
phenomenon is in some way dependent on the earth’s 
motion around the sun, and he was not long in reaching 
the correct explanation. For suppose the earth to be at 
rest. Then in observing a star at the pole of the ecliptic 
it would be necessary to keep the axis of the telescope 
exactly at right angles to the plane of the earth’s orbit. 
However, as the earth is in motion, the telescope must be 
pointed a little forward, just as in walking rapidly 
through the rain an umbrella must be inclined forward so 
as to intercept the raindrops which would otherwise fall 
on the spot to be occupied at the end of the next step. 
The angle through which the telescope has to be tilted is 
known as the angle of aberration, and the tangent of this 
angle may easily be shown to be equal to the ratio of the 
velocity of the earth to the velocity of light. Knowing 
the velocity of the earth, the velocity of ight can then be 


330 LL. Page—A Century’s Progress wm Physics. 


calculated. ‘This method was one of the first of obtaining 
the value of this important quantity. 

More recently, terrestrial methods of great precision 
have been devised for measuring the velocity of light. 
The most accurate of these is that employed by the 
French physicist Foucault in 1862. A ray of light is 
reflected by a rotating mirror to a fixed mirror placed at 
some distance, which in turn reflects the ray back to 
the moving mirror. The latter, however, has turned 
through a small angle during the time elapsed since the 
first reflection, and consequently the direction of the ray 
on returning to the source is not quite opposite to that in 
which it had started out. This deviation in direction is 
determined from the displacement of the image formed — 
by the returning light, and from it the velocity of light 
is calculated. In order to make the deflection appreci- 
able the distance between the two mirrors should be very 
great. As originally arranged by Foucault, it was 
found impractical to make this distance greater than 
twenty meters, and consequently the displacement of the 
image was less than a millimeter. Such a small deflection 
limited the accuracy of the experiment to one percent. 
In 1879, however, Michelson (18, 390, 1879), then a mas- 
ter in the United States Navy, improved Foucault’s opti- 
cal arrangements to such an extent that he was able to 
use a distance of nearly seven hundred meters between 
the two mirrors. With a rate of two hundred and fifty- 
seven revolutions a second for the rotating mirror, the 
displacement obtained was over thirteen centimeters. 
This experiment gave 299,910 kilometers a second for 
the velocity of light, with a probable error of one part in 
ten thousand. Later investigations by Newcomb and 
Michelson (31, 62, 1886) gave substantially the same 
result. So great has been the accuracy of these terres- 
trial determinations that recent practice has been to eal- 
culate from them and the angle of aberration the earth’s 
orbital velocity, and hence the distance of the earth from 
the sun. This indirect method of measuring the astro- 
nomical unit has a probable error no greater than the best 
parallax methods of the astronomer. (J. Lovering, 36, 
161, 1863.) 

Aberration is a first order effect, 2. e., it depends upon 
the first power of the ratio of the velocity of the earth to 
the velocity of light, and at first sight it seemed to prove 


L. Page—A Century’s Progress in Physics. 331 


conclusively that the earth must be in motion relative to 
the luminiferous medium. Other questions had to be set- 
tled, however, and one of these was whether or not light 
coming from a star would be refracted differently when 
passing through optical instruments from light which 
had a terrestial origin. Arago subjected the matter to 
experiment, and concluded that in every respect the light 
from a star behaved as if the earth were at rest and the 
star actually occupied the position which it appears to 
occupy on account of aberration. Finally optical exper- 
iments with terrestrial sources seemed to be in no way 
affected by the motion of the earth through the ether. 

In order to account for these facts Fresnel advanced 
the following theory. To explain the refraction that 
takes place when light enters a transparent body, it is 
necessary to assume that light waves travel more slowly 
through matter than in free ether. Now the velocity of 
sound is known to vary inversely with the square root of 
the density of the material medium through which it 
passes. Hence it is natural to assume that ether is con- 
densed inside material objects to such an extent that 
this same relation connects its density with the velocity 
of light traveling through it. But when a lens or prism 
is set in motion, Fresnel supposed it to carry along only 
the excess ether which it contains, ether of the normal 
density remaining behind. This assumption suffices to 
explain Arago’s results, and yet fits in with the phenom- 
enon of aberration. It gives for light traveling in the 
direction of motion through a moving material medium 
of index of refraction » an absolute velocity greater than 
that when the medium is at rest by an amount 


/ 1 
(! =) U, 


which is only a fraction of the velocity v which would 
have to be added if convected matter carried along all 
the ether which resides within it. This expression was 
tested -directly, first by Fizeau in 1851, and later by 
Michelson and Morley (31, 377, 1886) in this country. 
The experiment consists in bifureating a beam of light, 
passing one half in one direction and the other in the 
opposite direction through a stream of running water. 
On reuniting the two rays the usual interference fringes 
are produced. Reversing the direction of motion of the 


IH | 


382 LD. Page—A Century’s Progress in Physics. 


water causes the fringes to shift, and from the amount of 
this shift the velocity imparted to the light by the motion 
of the stream is computed. The divergence between the 
experimental value of this quantity and that calculated 
from Fresnel’s coefficient of entrainment was found by 
Michelson and Morley to be less than one percent, which 
was about their experimental error. Thus Fresnel’s 
expression for the velocity of light in a moving medium is 
entirely confirmed by experiment. ‘The derivation of it © 
accepted to-day, however, is very different from his orig- 
inal deduction. 

It has been noted that the phenomena of polarization 
led Newton to reject the wave theory of light. The only 
type of wave known to him was the longitudinal wave, 
in which the vibrations of the particles of the medium are 


in the same direction as that of propagation of the wave, 


and it was impossible to suppose that such a wave could 
have different properties in different directions at right 
angles to the line in which it is advancing. But in 1817 
Young suggested that this inconsistency between the 
wave theory and the facts of polarization could be 
removed by supposing the vibrations constituting light to 
be executed at right angles to the direction of propaga- 
tion. Thus in ordinary light the vibrations are to be 
conceived as taking place haphazard in all directions in 
the plane perpendicular to the ray, while in plane polar- 
ized light these vibrations are confined to a single 
direction. This supposition explained so many of the 
puzzling results of experiment, that it was accepted at 
once and led to ae complete vindication of the undula- 
tory theory. 

Elastic Solid Theory. —Shortly afterwards Poisson 
sueceeded in solving the differential equation which 
determines the motion of a wave through an elastic 
medium. His solution shows that. such a medium is 
capable of transmitting two types of wave—one longi- 
tudinal, the other transverse. If k denotes the volume 
elasticity, 7 the rigidity and p the density of the medium, 
the velocities of the two waves are respectively 


Je +40 and a 
4 p iy p 


Now a solid has both compressibility and rigidity, 
and transmits in general both types of wave. A 


2. 


L. Page—A Century’s Progress in Physics. 333 


fluid, on the other hand, on account of its lack of 
rigidity, cannot support a transverse vibration. Hence 
it was natural that Green, in searching for a dynamical 
explanation of the ether, should have proposed in a paper 
read before the Cambridge Philosophical Society in 
1837 that the ether has the elastic properties of a solid. 
One great difficulty presented itself; disturbances 
inside an elastic solid must give rise to compressional as 
well as to transverse waves. But no such thing as a 
compressional wave had been found in the experimental 
study of hght. Green attempted to overcome this diffi- 
eulty by attributing an infinite volume-elasticity to the 
ether. The expression above shows that longitudinal 
waves originating in such an incompressible medium 
would be carried away with an infinite velocity, and it 
may be shown that the energy associated with them 
would be infinitesimal in amount. The next step was to 
caleulate the coefficients of transmission and reflection 
for light passing from. one material medium to another. 
Here the elastic solid theory is not altogether successful. 
If the ether is supposed to have different densities in the 
two media, as in F’resnel’s theory, but the same rigidity, 
certain of these coefficients fail to give the values 
demanded by experiment, while if the densities are 
assumed the same but the rigidities different, other of the 
coefficients have discordant values. In connection with 
the phenomena of double refraction even more serious 
difficulties are encountered. 

Electromagnetic Theory.—It was beginning to be felt 
that an ether must explain more than the phenomena of 
light, for Faraday’s conception of electromagnetic 
action as carried on through the agency of a medium 
had added greatly to its functions. Finally Maxwell’s 
demonstration that electromagnetic waves are propa- 
gated with the velocity of lhght made the theory 
of hight into a subdivision of electrodynamics. Maxwell 
himself did not apply electromagnetic theory to the 
explanation of reflection and refraction. This defi- 
ciency, however, was remedied by Lorentz in 1875. The 
results obtained, as well as those for double refraction 
(J. W. Gibbs, 23, 262, 1882 et seq.), and metallic reflec- 
tion (L. P. Wheeler, 32, 85, 1911), provided a complete 
vindication of the electromagnetic theory of light. This 
is all the more significant when the extreme precision 


3384 LL. Page—A Century’s Progress in Physics. 


obtainable in optical experiments is taken into account. 
For instance, Hastings (35, 60, 1888) has tested Huy- 
gens’ construction for double refraction in Iceland spar 
and found that ‘‘the difference between a measured index 
of refraction ... at an angle of 30° with the crystalline 
axis, and the index calculated from Huygens’ law and 
the measured principal indices of refraction’’ is a matter 
of only 4:5 units in the sixth decimal place. Since Max- 
well’s time the gamut of electromagnetic waves has been 
steadily extended. The shortest Hertzian waves merge 
almost imperceptibly into the longest heat waves of the 
infra-red, and from there the known spectrum runs con- 
tinuously through the visible region to the short waves 
of the extreme ultra-violet recently disclosed by Lyman. 
Here there is a short gap until soft X-rays are reached, 
and finally the domain of radiation comes to an end with 
gamma rays a billionth of a centimeter in length. 

Maxwell’s ether was not a dynamical ether in the sense 
of Green’s elastic solid medium. In spite of the fact that 
Maxwell was always active in devising mechanical ana- 
logues to illustrate the phenomena of electromagnetism, 
he was never enthusiastic over the speculations of the 
advocates of adynamical ether. The electrodynamic equa- 
tions provided an accurate representation of the electric 
and magnetic fields, and beyond that he felt it was need- 
less to go. That Gibbs (23, 475, 1882) held the same 
view is made evident by the closing paragraphs of a 
paper in which he shows that the electromagnetic theory 
of light accounts in minutest detail for the intricate phe- 
nomena accompanying the passage of light through cir- 
cularly polarizing media. He says: 


‘“The laws of the propagation of light in plane waves, which 
have thus been derived from the single hypothesis that the dis- 
turbance by which light is transmitted consists of solenoidal 
electrical fluxes, . . . are essentially those which are received 
as embodying the results of experiment. In no particular, so 
far as the writer is aware, do they conflict with the results of 
experiment, or require the aid of auxiliary and forced hypotheses 
to bring them into harmony therewith. 

In this respect the electromagnetic theory of light stands in 
marked contrast with that theory in which the properties of an 
elastic solid are attributed to the ether,—a contrast which was 
very distinct in Maxwell’s derivation of Fresnel’s laws from 
electrical principles, but becomes more striking as we follow the 
subject farther into its details, and take account of the want of 


L. Page—A Century’s Progress wm Physics. 335 


absolute homogeneity in the medium, so as to embrace the 
phenomena of the dispersion of colors and circular and elliptical 
polarization.”’ 


Further Dynanucal Theories.—Kelvin, however, was 
not satisfied with this type of ether. To him dynamics 
was the foundation of all physical phenomena, and noth- 
ing could be said to be explained until a mechanical model 
was provided. So he returned to the elastic solid theory, 
and developed the consequences of the assumption, 
already made use of by Cauchy, that the ether has a nega- 
tive volume elasticity of such a value as to make the 
velocity of the compressional wave zero. In order to 
prevent such an ether from collapsing it is necessary to 
assume that it is rigidly attached at its boundaries and 
that cavities cannot be formed at any point in its interior. 
Now Gibbs (37, 129, 1889) has pointed out the remark- 
able fact that the equations describing the motion of 
Kelvin’s quasi-labile ether are of exactly the same form 
as the electromagnetic equations. Electric displacement 
is represented by an actual displacement of the ether, 
magnetic intensity by a rotation. Hence everything 
which can be explained by the electrodynamic equations 
finds an analogue in terms of Kelvin’s ether. Still 
another type of dynamic ether which fits the known facts 
was proposed by McCullagh and perfected by Larmor. 
In this ether a rotational elasticity 1s premised, such as 
would exist if each particle of the medium consisted of 
three rigidly connected gyrostats with mutually perpen- 
dicular axes. In this ether electrical displacements cor- 
respond to rotations, and magnetic strains to etherial dis- 
placement. 

A New Point of View.—While the dynamical school 
was still dominant in England, another point of view 
was developing on the continent. Kirchhoff denied 
that it was the province of science to provide mechanical 
explanations of the ether and electrodynamic phenomena 
such as Kelvin conceived to be necessary in order to make 
these- phenomena intelligible. Kuirchhoff’s contention 
was that the object of science is purely descriptive,— 
phenomena must be observed, classified, and mutual con- 
nections described by the fewest number of differential 
equations possible. Mach expressed the same idea 
somewhat more concisely when he asserted that the aim 
of science is ‘‘economy of thought.’’? For instance, in 


336 DL. Page—A Century’s Progress in Physics. 


the time of Newton, planetary motions could be described 
quite satisfactorily by means of the three laws of Kepler. | 
The motion of falling bodies on the earth’s surface had 
been described with a fair degree of accuracy by Galileo. 
The value of Newton’s law of gravitation, however, lay in 
the fact that this great generalization made it possible to 
describe these and many other types of motion by a 
single simple formula, instead of leaving each to be gov- 
erned by a number of separate and apparently unrelated 
laws. The importance of such a generalization is meas- 
ured by the economy of thought which it introduces. 
Electron Theory.—The electron theory was leading to 
a reversal of Kelvin’s idea that dynamical principles 
must underlie electrodynamics. Lorentz had shown that 
a rigorous solution of the electrodynamic equations did 


Fie. 1. Fig, 2. Hie a: 


away entirely with Maxwell’s displacement current, but 
made the electromagnetic field at a point in space depend 
not upon the distribution of charges and currents at the 
same instant, but at a time earlier sufficient to allow the 
effect to travel with the velocity of hght from the charges 
and currents producing the field to the point at which the 
electric and magnetic intensities are to be found. The 
position of acharge or current element at this earlier time 
he denoted its ‘‘effective position.’’ The effective distri- 
bution, then, is that actually seen by an observer stationed 
at the point under consideration at the instant for which 
the intensity of the electromagnetic field is to be deter- 
mined. This solution of the electrodynamic equations 
led in turn to rigorous expressions for the electric and 
magnetic intensities produced by a very small charged 
particle, such as an electron. Fig. 1 shows the electro- 
static field produced by a charged particle at rest. -The 


L. Page—A Century’s Progress mm Physics. 387% 


lines of force spread out radially and uniformly in all 
directions. In fig. 2 the electron is supposed to have a 
velocity v horizontally to the right of an amount smaller 
than, though comparable with, the velocity of hght c. 
It is seen that the lines of electric force still diverge 
radially from the charge, but are crowded in the equato- 
rial plane and spread apart in the polar regions. The 
dissymmetry grows as the velocity increases until if the 
velocity of hght should be reached the field would be 
entirely concentrated in a plane at right angles to the 
direction of motion. Now it may be shown that fig. 2 is 
obtainable from fig. 1 by reducing diumensions in the 
direction of motion in the ratio of 


ants MEER Re v 
vie ea: | where B= or 


For a uniformly convected electric field differs from an 
electrostatic field only in that the dimensions in the direc- 
tion of motion are contracted in this particular ratio. 
Fig. 3 represents the electric field of a charged particle 
which has a uniform acceleration to the right. Consider 
Faraday’s analogy between lines of force and stretched 
elastic bands. The symmetry of the first two figures 
shows that in neither of these cases would there be a 
resultant force on the charged particle. But in the third 
figure it is obvious that a force to the left is exerted on 
the charge by its own field. Calculation shows this force 
to be proportional in magnitude to the acceleration. Let 
it be postulated that the resultant force on a charged 
particle is always zero. Then if F' is the applied force, 
the force on the particle due to the reaction of its field 
will be —-m f, where f stands for the acceleration and m 
is a positive constant, and we have the fundamental 
equation of dynamics 
F—mf=0 

Hence, instead of admitting Kelvin’s contention that all 
physical phenomena must be given a mechanical explana- 
tion, 1t-would seem more logical to assert that electro- 
dynamics actually underlies mechanics. 

Calculation shows the electromagnetic mass m to vary 
inversely with the radius of the charged particle. Now 
Thomson’s experiments made it possible to calculate the 
mass of an electron. Hence its radius can be computed, 
and is found to be about 2(10)+* part of a centimeter, or 


SS. 


ms 


= 


338 LL. Page—A Century’s Progress in Physics. 


one fifty-thousandth part of the radius of the atom. 
Since numbers so small convey little meaning, consider 
the following illustration, due, in part, to Kelvin. 
Imagine a single drop of water to be magnified until it is 
as large as the earth. The individual atoms would then 
have the size of baseballs. Now magnify one of these 
atoms until it is comparable in size with St. Peter’s 
cathedral at Rome. The electrons within the atom would 
appear as a few grains of sand scattered about the nave. 
This separation between the constituent electrons of the 
atom,—so great in comparison with their dimensions,— 
explains how alpha particles can be shot by the billion 
through thin-walled glass tubing without leaving any 
holes behind or impairing in the slightest degree the high 
vacuum within the tube. The much smaller high-speed 
beta particles pass through an average of ten thousand 
atoms without even coming near enough to one of the 
component electrons to detach it and form an ion. 

Michelson-Morley Experrment.—In 1881 Michelson 
(22, 120, 1881) conceived an ingenious and bold method 
of measuring the orbital motion of the earth through the 
luminiferous ether. As the experiment was one involv- 
ing considerable expense, Bell, the inventor of the tele- 
phone receiver, was appealed to successfully for the 
funds necessary to carry it through. Michelson’s ~ 
experimental plan was as follows: A beam of lght 
traveling in the direction of the earth’s motion strikes 
an unsilvered mirror m at an angle of 45°. Part of the 
light passes through, the rest being reflected at right 
angles to its original direction. Hach ray is returned by 
a mirror at a distance] from m. On meeting again, the 
ray whose path has been at right angles to the direction 
of the earth’s motion passes on through the mirror, while 
the other ray is reflected so as to bring the two in line 
and form interference fringes. Now consider the effect 
of the earth’s motion on the paths of the two rays. In 
fiz. 4 the earth is supposed to be moving to the right. 
The unsilvered mirror m bifureates a beam of hight com- 
ing from a source a. By the time the ray reflected from 
m has traveled to the mirror b and back, m will have 
moved forward to m’; a distance 281, where the small 
quantity @ is the ratio of the earth’s velocity to the 
velocity of light. Hence the length of the path traversed 
by this ray 1s approximately 


L. Page—A Century’s Progress in Physics. 339 


21 (: ~ = g") : 
The other ray will reach the mirror c after the latter has 
moved forward a distance 


Bl 
De 
and on returning find m at m’. Hence its path has a 
length of roughly 2/ (1+ 87). The difference in path of 


Fie. 4. | 


b 


the two rays is 67/1 and consequently they should be a 
little out of phase on meeting at d. By rotating the 
apparatus clockwise through 90° the directions of the 
two rays relative to the earth’s motion are interchanged, 
and the interference fringes would be expected to shift 
an amount corresponding to a difference in path of 2 6? l. 
This quantity is of course small,—? is about one one- 
hundred millionth,—but so sensitive are the methods of 
interferometry that Michelson felt confident that he 
would be able to detect the earth’s motion through the 
ether. The apparatus consisted of a table which could 
be rotated about a vertical axis in much the same way 
as a spectrometer table, and provided with arms a meter 
long to carry the mirrors b and c. With this length of 
arm the interference fringes from sodium light should 
shift by an amount corresponding to four hundredths of 


340 L. Page—A Century’s Progress m Physics. 


a wave length when the table is rotated through a right 
angle. When the experiment was first performed the 
apparatus was placed ona stone pier in the Physical Insti- 
tute at Berlin. So sensitive was the instrument to outside 
vibrations that even after midnight it was found impos- 
sible to get consistent readings. Finally a satisfactory 
foundation was constructed in the cellar of the Astro- 
physical observatory at Potsdam. But what was the 
astonishment of the experimenters to find that the 
expected shift of the interference fringes did not exist! 

The extreme delicacy of the experiment made it desir- 
able to confirm the result by repeating it. This was 
done by Michelson and Morley (34, 333, 1887) in 1887. 
In place of a revolving table a massive slab of stone 
floating on mercury was used to carry the apparatus. 
This slab was kept in constant rotation, the observer 
following it around. Moreover, the precision of the 
experiment was greatly increased by reflecting each ray 
back and forth across the slab a number of times between 
leaving and returning to the mirror m. The accuracy 
attained was such as to justify Michelson in declaring 
that if the effect sought actually existed it could not be 
so great as one-twentieth of its calculated value. In 
1905 Morley and Miller'® repeated the experiment for the 
second time and succeeded in increasing the sensitiveness 
of the apparatus to a point such that a motion through 
the ether of one-tenth of the earth’s orbital velocity 
could have been detected. 

The displacement looked for in the Michelson-Morley 
experiment is known as a second-order effect in that it 
depends upon the square of the ratio of the velocity of the 
earth to that of light. Michelson at first considered that 
the negative result obtained confirmed a theory proposed 
by Stokes in which it was assumed that the ether inside 
and near its surface partakes of the motion of the earth, 
while that at a distance is practically quiescent. But 
there are many objections to Stokes’ theory, one of which 
was brought out by an experiment of Michelson’s (3, 475, 
1897) in which he attempted by an interference method 
to detect a difference in the velocity of light at different 
levels above the earth’s surface. The negative result 
obtained led him to conclude that if Stokes’ theory were 

KE. W. Morley and D. C. Miller, Phil. Mag., 9, 680, 1905. 


L. Page—A Century’s Progress m Physics. 3841 


true the earth’s influence on the ether would have to 
extend to a distance above its surface comparable with 
its diameter. Meanwhile a more satisfactory explana- 
tion was forthcoming. It has been pointed out that a 
uniformly convected electric field is derivable from an 
electrostatic field by contracting dimensions in the direc- 
tion of motion in the ratio 


OI pense 
Fitzgerald and Lorentz showed independently that if 
moving matter is distorted in this same way the result 


obtained by Michelson would be just that to be expected. 
For then the distance of the mirror ¢ from m would be 


Lr/i — 
instead of J, and the path of the ray moving parallel to 
the earth’s orbit 
1 2 
21 ( pM ee i 


which is just that of the other ray. Of course when the 


- apparatus is rotated-.through 90°, the distance of this 


mirror from m assumes its normal value again, and the 
distance of the other mirror becomes shortened. As all 
measurement consists in comparing the object to be 
measured with a standard this contraction could never 
be detected by experimental methods, for the measuring 
rod would contract in exactly the same ratio as the body 
to be measured. 

In computing its electromagnetic mass Abraham had 
assumed the electron to be a uniformly charged rigid 
sphere which keeps its spherical form no matter how 
ereat a velocity it may be given. He found that the mass 
increases with the speed at very high velocities, becom- 
ing infinite as the velocity of light is approached, and 
that its value depends upon the direction of the applied 
force. After the Fitzgerald-Lorentz contraction was 
seen to be necessary in order to explain Michelson’s 
result, Lorentz calculated the electromagnetic mass of a 
charged sphere which is deformed into an oblate spheroid 
when set in motion. For this type of electron too, the 
mass approaches infinity for velocities as great as that of 
hght, and is different for different directions. If a 
force is applied in the direction of motion the inertia to 


342 LDL. Page—A Century’s Progress:im Physics. 


be overcome is a little greater than when the force is 
apphed at right angles to this direction. Thus we | 
have to distinguish between longitudinal and transverse 
masses. But the masses of Lorentz’s electron are not 
the same functions of its velocity as those of Abraham’s. 
Kaufmann and after him Bucherer tested experimentally 
the relation between transverse mass and velocity by 
observing the deflections produced by electric and mag- 
netic fields in the paths of high speed beta particles. 
The latter’s work was such an ample confirmation of 
Lorentz’s formula that it may be considered as proven 
that a moving electron at least suffers contraction in ae 
direction of motion in the ratio 


A) Beale 


The electromagnetic theory of light had proved so 
successful when applied to bodies at rest that Lorentz 
was anxious to extend this theory to the optics of moving 
media. His problem was to find a group of homogeneous 
linear transformations that would leave the form of the 
electrodynamic equations unchanged. The Michelson- 
Morley experiment had shown that dimensions in the 
direction of motion must be contracted in the moving 
system, those at right angles remaining unaltered. But 
Lorentz soon found that it was also necessary to use a 
new unit of time in the moving system, and as this time 
was found to depend upon the position of the point at 
which it is to be determined, he called it the local time. 
Lorentz’s transformation is just that of the principle 
of relativity, but he did not succeed in expressing the 
electrodynamic equations in terms of the new coordinates 
and time in exactly the same form as for a system at 
rest, for the reason that he failed to endow these new 
units with sufficient reality to justify him in using them 
when it came to transforming the velocity term involved 
in an electric current. 

Principle of Relatiwity—kIn 1905 appeared in the 
Annalen der Physik'* a paper destined to alter entirely 
the point of view from which problems in light and elec- 
tromagnetic theory are to be approached. The author 
was Albert Einstein, of Berne, Switzerland, a young man 
of twenty-six who had already made a number of notable 
contributions to theoretical physics. 

417, 891, 1905. 


L. Page—A Century’s Progress in Physics. 848 


The principle of relativity proposed by Einstein was 
by no means new to students of dynamics. Newton’s 
first two laws of motion express very clearly the fact that 
in mechanics all motion is relative. Force is propor- 
tional to acceleration, and the relation between the two 
is the same whether the motion under consideration is 
referred to fixed axes or to axes moving with a constant 
velocity. But in connection with the phenomena of light 
and electromagnetism the case seemed to be quite differ- 
ent. There everything was referred to a fixed ether, and 
even though Lorentz had found a set of transformations 
which left the electrodymanic equations practically 
unchanged, he continued to think in terms of an ether. 
So physicists were not a little startled when Einstein 
postulated that no experiment, practical or ideal, could 
ever distinguish between two systems in such a manner 
as to warrant the assertion that one of them is at rest 
and the other in motion. All motion is relative, and the 
laws governing physical, chemical and biological phe- 
nomena are the same in terms of the units of one system 
as in terms of those of any other. 

Hinstein next considers some very fundamental ques- 
tions. What do we mean when we say that two events, 
one at A and the other at a point B far from A, occur at 
the same time? Obviously the expression has no signi- 
ficance unless synchronous clocks are stationed at the 
two points. But how is it to be determined whether or 
not these two clocks are synchronous? If instantaneous 
communication could be established between A and B 
the matter would be simple enough. Since no infinite 
velocity of transmission is available, however, let a light 
wave be sent from A to B and returned to A immediately 
upon its arrival. If the time indicated by the clock at 
B when the signal is received is half way between that at 
which it left A and the time at which it arrives on its 
return, then the two clocks may be considered syn- 
chronous. Now if it desired to measure the length of a 
bar which is moving parallel to the scale with which the 
measurement is to be made, it is necessary to note the 
positions of the two ends of the bar at the same instant. 
So even the measurement of the length of a moving body 
depends upon the condition of synchronism at different 
points in space. 

The principle of relativity requires that the velocity 


344 I. Page—A Century’s Progress m Physics. 


of light shall be the same in one system as in another 
relative to which the first is in motion. Hence the 
definition of synchronism makes it possible to obtain a 
set. of transformations connecting space and time meas- 
urement on one system with those on another. This 
group of transformations is exactly that which Lorentz 
had found would transform the electrodynamic equations 
into themselves. But Hinstein’s point of view brought 
out a remarkable reciprocity which Lorentz had missed. 
If two parallel rods MN and OP are in motion relative to 
each other in the direction of their lengths, not only does 
OP appear shortened to an observer at rest with respect 
to MN, but MN appears shorter than normal in the 
same ratio to an observer. who is moving along with the 
rod OP. 

Hinstein’s theory makes the velocity of ight the maxi- 
mum speed with which a signal can be transmitted. This 
leads to his celebrated addition theorem. Consider three 
observers A, B and C. Let B be moving relative to A 
with a velocity of nine-tenths the velocity of ight, and C 
in the same direction with an equal velocity relative to B. 
In terms of old-fashioned notions of time and space, the 
velocity of C relative to A would be computed as one and 
eight-tenths the velocity of light. But the relativity 
theory gives it as ninety-nine hundredths the velocity of 
light. For the velocity of light can never be surpassed 
by that of any material object. This deduction from 
theory is most strikingly confirmed by the fact that 
although beta particles have been observed with velocities 
as high as ninety-nine hundredths that of light, the 
velocity of lght is never quite equalled. It may be 
remarked in passing that the principle of relativity 
requires that the masses of all material bodies shall vary 
with the velocity in the same manner as Lorentz found 
to be the case for the electromagnetic mass of the deform- 
able electron. In this connection Bumstead (26, 498, 
1908) has devised an elegant method of deducing the 
ratio of longitudinal to transverse mass. 

The close connection between electrodynamics and the 
principle of relativity is obvious from the fact that both 
lead to the same time and space transformations. Fur- 
thermore L. Page (37, 169, 1914) has shown that the 
electrodynamic equations can be derived exactly and in 
their entir ety from nothing more than the kinematics of 


L. Page—A Century’s Progress im Physics. 345 


relativity and the assumption that every element of 
charge is a center of uniformly diverging lines of force. 
Hence it may safely be asserted that no purely electro- 
magnetic phenomenon can ever come into contradiction 
with this principle. The simplicity thus introduced into 
the solution of a certain class of problems is enormous. 
As an example consider the question as to whether a mov- 
ing star is retarded by the reaction of its own radiation. 
This purely electrodynamical problem is of such com- 
plexity that attempts to solve it have led to some contro- 
versy among mathematical physicists. The principle of 
relativity tells us without recourse to analysis that no 
retardation can exist. 

Throughout the nineteenth century the ether has 
played a fundamental part in all important physical 
theories of ight and electromagnetism. But if it is not 
possible for experiment to detect even the state of 
motion of the ether, why postulate the existence of such a 
medium? If it does not possess the most fundamental 
characteristic of matter, how can it possess such derived 
properties as density and elasticity,—properties which 
any conceivable mechanical medium must have in order 
to transmit transverse vibrations? The relativist does 
not deny the existence of an ether. To him the question 
has no more meaning than if he were asked to express an 
opinion as to the reality of parallels of latitude on the 
earth’s surface. As a convenient medium of expression 
in describing certain phenomena the ether has justified 
much of the use which has been made of it. But to 
attribute to it a degree of substantiality for which there 
is no warrant in experiment, is to change it from an aid 
into an obstacle to the progress of science. From the 
relativist point of view the distinction is very sharp 
between those motions of charged particles which are 
experimentally observable, and such geometrical conven- 
tions as electromagnetic fields, or analytical symbols as 
electric and magnetic intensities. These modes of repre- 
sentation have been and still are of the greatest use and 
importance, but their value in scientific description must 
not lead to lack of appreciation of their purely specula- 
tive character. 

Finally attention must be drawn to the fact that the 
discoveries of inductive science, embodied in the great 
generalization we have just been discussing, have led to 
a more intimate knowledge of the nature of time and 


346 LL. Page—A Century’s Progress im Physics. 


space than twenty centuries of introspection on the part 
of professional philosophers. Minskowski, whose prom- 
ise of greater achievement was cut off by an untimely 
death, has shown that four dimensional geometry makes 
possible the representation with beautiful simplicity of 
the time and space relationships of this theory. The 
one time and three space dimensions merge in such a 
manner as to form a single whole with not a vestige of 
differentiation between these fundamental quantities. 
Wilson and Lewis'® have made this representation famil- 
iar to American readers through their admirable trans- 
lation of Minskowski’s work into the notation of Gibbs’s 
vector analysis. 

Aberration, the Doppler effect, anomalous dispersion, 
—indeed all known phenomena, —are found to be in 
accord with the principle of relativity. It must be 
borne in mind, however, that this principle applies only 
to systems moving relative to one another in straight 
lines with constant velocities. That there is something 
absolute about rotation has been recognized since F'ou- 
cault performed his famous pendulum experiment in 1851. 
This experiment (C. 8S. Lyman, 12, 251 and 398, 1851) 
consisted in setting a pendulum composed of a heavy 
brass ball suspended by a long wire into oscillation in 
such a way as to avoid appreciable ellipticity in its 
motion. Observation of the rate at which the ground 
rotates relative to the plane of vibration of the pendulum 
furnished a method of measuring the rotation of the 
earth about its axis without reference to celestial bodies. 
The gyroscopic compass in use to-day provides vet 
another terrestial method of detecting this rotation. 

The Future of Physics —At times during the history 
of physics it has seemed as if the fundamental laws of 
this science had been so completely formulated that 
nothing remained to future generations beyond the 
routine of deducing to the full the consequences of these 
laws, and increasing the precision of the methods used 
to measure the constants appearing in them. That 
Laplace held this view has already been pointed out, and 
Maxwell, in his introductory lecture at the opening of the 
Cavendish laboratory in 1871, said, ‘‘This characteristic 
of modern experiments—that they consist principally of 
measurements—is so prominent, that the opinion seems 


1°, B. Wilson and G. N. Lewis, Proc. Am. Acad. of Arts and°Sci., 48, 
389, 1912. | 


L. Page—A Century’s Progress in Physics. 347 


to have gotten abroad that in a few years all the great 
physical constants will have been approximately esti- 
mated, and that the only occupation which will then be 
left to men of science will be to carry on these measure- 
ments to another place of decimals.’’ That he himself 
did not entertain this view is made evident by a succeed- 
ing paragraph. ‘‘But we have no right to think thus of 
the unsearchable riches of creation, or of the untried fer- 
tility of those fresh minds into which these riches will 
continue to be poured. It may possibly be true that, in 
some of those fields of discovery which lie open to such 
rough observations as can be made without artificial 
methods, the great explorers of former times have 
appropriated most of what is valuable, and that the 
gleanings which remain are sought after rather for their 
abstruseness than for their intrinsic worth. But the his- 
tory of science shows that even during that phase of her 
progress in which she devotes herself to improving the 
accuracy of the numerical measurement of quantities 
with which she has long been familiar, she is preparing 
the materials for the subjugation of new regions, which 
would have remained unknown if she had been contented 
with the rough methods of her early pioneers. .. .’’ 
That Maxwell’s forecast of the prospects of his science 
was no overestimate will be granted by those who have 
followed the progress of physics during the last twenty 
vears. Yet the work accomplished in the past appears 
small compared to that which is left to the future. Many 
of the unsolved problems are matters of fitting together 
puzzling details, but there is at least one whose solution 
appears to demand a radical modification in our funda- 
mental physical conceptions. ‘This is the formulation of 
the laws which govern the motions of electrons and pos- 
itively charged particles inside the atom. | 
Black Radiation.—The significance of the problem was 
first brought to hght through the study of black radia- 
tion. By a black body is meant one whose distinguishing 
characteristic is that it emits and absorbs radiation of all 
frequencies, and black radiation is that which will exist in 
thermal equilibrium with such a body. The interest of 
this type of radiation les in the fact, demonstrated by 
Kirchhoff, that its nature depends only upon the temper- 
ature of the black body with which it is in equilibrium, 
and on none of this body’s physical or chemical charac- 
teristics. Thus we may speak of the ‘‘temperature’’ of 


3848 LL. Page—A Century’s Progress in Physics. 


the radiation itself, meaning by this the temperature of 
the material body with which it would be in equilibrium. 

The problem of black radiation is to find the distribu- 
tion of energy among the waves of different frequencies 
at any given temperature. The first step toward a solu- 
tion was made when Stefan showed experimentally, and 
Boltzmann as a deduction from thermodynamics and 
electrodynamics, that the total energy density summed 
up over all wave lengths varies with the fourth power of 
the absolute temperature. If the energy density is 
plotted as ordinate against the wave length as abscissa, 
the experimental curve for any one temperature rises 
from the axis of abscissas at the origin, reaches a maxi- 
mum, and falls to zero again as the wave length becomes 
infinitely great. Now Wien’s displacement law, the 
second important step toward the determination of the 
form of this curve, shows that as the temperature is 
raised the wave length to which its highest point cor- 
responds becomes shorter,—in fact this particular wave 
length varies inversely with the absolute temperature. 
This theoretical conclusion is entirely confirmed by 
experiment. (J. W. Draper, 4, 388, 1847.) | 

Farther than this general thermodynamical princi- 
ples are unable to go. Statistical mechanics, however, 
asserts that when a large number of like elements are in 
thermal equilibrium, the average kinetic energy asso- 
ciated with each degree of freedom is equal to a universal 
constant multiplied by the absolute temperature. This 
‘‘yorinciple of equi-partition of energy’’ has been applied 
in various ways to obtain a radiation law. The most 
straightforward method is based on the equilibrium 


which must ensue between radiation field and material 


oscillators when the latter emit, on the average, as much 
energy as they absorb. From whatever aspect the prob- 
lem is treated, however, the radiation law obtained from 
the application of the equi-partition principle is the same. 
And while this law agrees well with the experimental 
curve for long wave lengths, it shows an energy density 
that becomes indefinitely great for extremely short 
waves, which is not only at variance with the facts, but 
actually leads to an infinite value of this quantity when 
integrated over the entire spectrum. 

The Energy Quantum—Now the principle of equi- 
partition of energy rests securely on most general 
dynamical principles. That these dynamical laws are 


L. Page—A Century’s Progress m Physics. 349 


inexact to any such extent as the divergence between 
theory and experiment would indicate, is inconceivable ; 
that they are wsufficient when applied to motions of elec- 
trons in such intense fields as occur within the atom 
seems no longer open to doubt. In order to obtain a 
radiation formula in accord with experiment Planck has 
found it necessary to extend the atomic idea to energy, 
which he conceives to exist in multiples of a fundamental 
quantum hv, v being the frequency and h Planck’s con- 
stant. That some such hypothesis of discontinuity is 
essential in order to obtain any law that will even 
approximately fit the experimental facts has been proved 
by Poincaré. But the precise spot at which the quantum 
is introduced differs for every new derivation of Planck’s 
law. As deduced most recently by Planck himself, the 
quantum shows itself in connection with the emission of 
energy by the material oscillators with which the radi- 
ation field is in equilibrium. These oscillators are sup- 
posed to act quite normally in every respect except 
emission; here the radiation demanded by the electro- 
dynamic equations is cast aside, and an oscillator is 
supposed to emit at once all its energy after it has accu- 
mulated an amount equal to some integral multiple of hv. 
A form of the theory which does not contain this improb- 
able contradiction of the firmly established facts of 
electrodynamics introduces the quantum into the specifi- 
eation of the energy of vibration which is permitted to 
each oscillator. Here both emission and absorption fol- 
low the classical theory, but the motion of an emitting 
and absorbing linear oscillator of frequency v is supposed 
to be stable only for those amplitudes for which the energv 
of its oscillations is an integral multiple of hy. In order 
to maintain the energy at these particular values, the 
oscillator may draw energy from, or deposit surplus 
energy with, other degrees of freedom which partake 
neither in emission nor absorption, but act merely as 
storehouses. . 

Photoelectric Effect—When investigating the produc- 
tion of electromagnetic waves, Hertz had noticed that a 
spark passed more readily between the terminals of his 
oscillator when the negative electrode was illuminated by 
hight from another spark. Further investigation by 
Hallwachs, Elster and Geitel, and others showed that this 
effect was due to the emission of electrons by a metal 
exposed to the influence of ultra-violet light. Lenard 


350 L. Page—A Century’s Progress in Phystes. 


discovered that the energy with which a negatively 
charged particle is ejected is entirely independent of the 
intensity of the light, and further investigation showed 
it to depend only on the frequency. Einstein suggested 
that the electrons appearing in this so-called photo-elec- 
tric effect start from within the metal with an initial 
energy hv. In passing through the surface a resistance 
is encountered, however, so he concluded that the energy 
with which the fastest moving electrons appear outside 
the metal should be equal to hy less the work done in 
overcoming this resistance. Recent experiments not 
only confirm this relation, but provide a most satisfac- 
tory method of determining the value of h. Mullikan*® 
finds it to be 6-57(10)2" ergs sec., which gives the quan- 
tum for yellow light a value sixty times as great as the 
heat energy of a monatomic gas molecule at 0°C. That 
this large amount of energy can be transferred from the 
incident light to the ejected electron is quite out of the 
question ; ‘it must come from within the atom. In this 
way some indication is obtained of how vast intra-atomic 
energies must be. | 

Structure of the Atom.—The generally accepted model 
of the atom is that due chiefly to Rutherford.1* He con- 
siders it to be constituted of electrons revolving about a 
positive nucleus either singly or grouped in concentric 
rings, in much the same manner as the planets revolve 
around the sun. Experiments on the scattering of alpha 
rays, however, show that the nucleus, while it must have 
a positive charge sufficient to neutralize the charges of 
all the electrons moving around it, cannot have a volume 
of an order of magnitude greater than that of the elec- 
tron. The number of unit charges residing on it, except 
in the case of hydrogen, which is supposed to consist of a 
singly charged nucleus and only one electron, is found to 
be approximately half the atomic weight. Thus helium, 
with an atomic weight of about four, has a doubly 
charged nucleus with two electrons revolving about it, 
and lithium a triply charged nucleus and three electrons. 
The number of unit charges on the nucleus is supposed to 
correspond with the atomic number used by Moseley in 
interpreting the results of his experiment on the X-ray 
spectra of the elements. 

Now the electron which is revolving around the posi- 


7% R. A. Millikan, Phys. Rev., 7, 355, 1916. 
™ KH. Rutherford, Phil. Mag., 21, 669, ual 


L. Page—A Century’s Progress in Physics. 351 


tive nucleus of a hydrogen atom, must, according to elec- 
trodynamic laws, radiate energy. This radiation will 
act as a resistance to its motion, causing its orbit to 
become smaller and its frequency to increase. Hence 
luminous hydrogen would be expected to give off a con- 
tinuous spectrum. The very fine lines actually found 
seem inexplicable on the classical dynamical and electro- 
dynamical theories. These lines, and those of many 
other spectra, may even be grouped into series, and the 
relations between them expressed in mathematical form. 
Formule have been proposed by Balmer, Rydberg, Ritz 
and others, all of which contain a universal constant N 
as well as certain parameters which must be varied by 
unity in passing from one line of a series to the next. 

In 1913 Bohr'* proposed an atomic theory which brings 
to hight a remarkable numerical relationship between 
this quantity N and Planck’s constant h. He postulated 
that the electron in the hydrogen atom, for instance, can- 
not revolve in a circle of any arbitrary radius, but is con- 
fined to those orbits for which its kinetic energy is an 
integral multiple of 4hn, n being its orbital frequency. 
Now at times this electron is supposed to jump from an 
outer to an inner orbit, when the excess energy of the first 
orbit over the second is radiated away. But the energy 
emitted is also taken to be equal to hv, where v is the fre- 
quency of the radiation. Hence v can be determined, and 
the expression obtained for it is exactly that given long 
before by Balmer as an empirical law. The most 
remarkable thing about it, however, is that Bohr’s result 
contains a constant involving h and the electronic charge 
and mass which has precisely the value of the universal 
constant N of Balmer’s and Rydberg’s formule. In all, 
the theory accounts for three series of hydrogen, and 
yields satisfactory results for helium atoms which have 
lost an electron, or lithium atoms which have a double 
positive charge. But for atoms which retain more than 
a single electron it seems no longer to hold. 

The three mentioned are only the most clearly defined 
of a growing group of phenomena in which the quantum 
manifests itself. Its significance and the alteration in 
our fundamental conceptions to which it seems to be 
leading is for the future to make clear. That it presents 
the most important and interesting problem as yet 
unsolved few physicists would deny. 

#8'N. Bohr, Phil. Mag., 26, 1, 1913 et seq. 


—————— 


352 LL. Page—A Century’s Progress in Physics. 


American Physicists—In attempting to cover the 
progress of physics during the last hundred years in the 
space of a few pages, many important developments of 
the subject have of necessity. remained untouched, and 
the treatment of many others has been entirely imade- 
quate. Among those appearing in this Journal of which 
no mention has been made are LeConte’s (25, 62, 1858) 
discovery of the sensitive flame and Rood’s (46, 173, 
1893) invention of the flicker photometer. However, 
enough has been recounted to indicate the pre-eminent 
position in the history of physics in America occupied by 
four men: Joseph Henry, of the Albany Academy, 
Princeton, and the Smithsonian Institution; Henry 
Augustus Rowland, of Johns Hopkins University; 
Josiah Willard Gibbs, of Yale; and Albert Abraham 
Michelson, of the United States Naval Academy, Case 
School of Applied Science, Clark University, and the 
University of Chicago. Of these, the last named has the 
distinction of being the only American physicist to have 
received the Nobel prize, though there is little doubt that 
the other three would have been similarly honored had 
not their important work been published prior to the 
institution of this award. All four occupy high places 
im the ranks of the world’s great men of science, and the 
investigations carried out by them and their fellow 
workers in America have given to their country a posi- 
tion in the annals of physics which is by no means insig- 
nificant. 

THE JOURNAL’S Part IN METEOROLOGY. 

The meteorological investigations published in the 
early numbers of this Journal have played an important 
role in establishing a correct theory of storms. Before 
the origin of the United States Signal Service in 1871 no 
systematic weather reports were issued by any govern- 
mental agency in this country, and consequently the work 
of collecting as well as interpreting meteorological data 
rested entirely in the hands of interested individuals and 
institutions. The earliest important studies of storms 
to appear in the Journal were contributed by Redfield of 
New York, whose first paper (20, 17, 1831) treated in 
considerable detail a violent storm which passed over 
Long Island, Connecticut and Massachusetts in 1821. 
He coneluded that ‘‘the direction of the wind at a partic- 
ular place, forms no part of the essential character of a 
storm, but is only incidental to that particular portion 


L. Page—A Century’s Progress m Physics. 353 


... of the track of the storm which may chance to 
become the point of observation, ... the direction of 
the wind being, in all cases, compounded of both the rota- 
tive and progressive velocities of the storm.’’ A few 
years later, analyses of twelve ‘‘gales and hurricanes of 
the Western Atlantic’’ (31, 115, 1837) led to the statement 
that the phenomena involved ‘‘are to be ascribed mainly 
to the mechanical gravitation of the atmosphere, as con- 
nected with the rotative and orbital movements of the 
earth’s surface.’’ In this paper is emphasized the fact 
that the wind may blow in diametrically opposite direc- 
tions at points near the storm center. ‘‘ While one ves- 
sel has been lying-to in a heavy gale of wind, another, not 
more than thirty leagues distant, has at the very same 
time been in another gale equally heavy, and lying-to 
with the wind in quite an opposite direction.’’ From an 
accompanying sketch showing wind directions, the reader 
would infer that, at this time, Redfield believed the 
motion of the air to be very nearly in circles about the 
storm center. The same idea is conveyed by a later 
paper (42, 112, 1842). Espy (39, 120, 1840) of Philadel- 
phia, however, claimed that observation showed rather 
that the wind blew inwards toward a central point, if the 
storm were round in shape, or toward a central line, if 
it were oblong. This view Redfield (42, 112, 1842) con- 
tested, and brought forth much evidence to prove its 
falsity. A later statement (1, 1, 1846) of his own theory 
is as follows: ‘‘I have never been able to conceive, that 
the wind in violent storms moves only in circles. On the 
contrary, a vortical movement... appears to be an 
essential element of their violent and long continued 
action, of their increased energy towards the center or 
axis, and of the accompanying rain. .. . The degree of 
vorticular inclination in violent storms must be subject, 
locally, to great variations; but it is not probable that, 
on an average of the different sides, it ever comes near to 
forty-five degrees from the tangent of a circle,—and 
that such average inclination ever exceeds two points of 
the compass, may well be doubted.’’ A qualitative 
explanation of the effect of the earth’s rotation on the 
direction of the wind near the storm center had already 
been given by Tracy (45, 65, 1843), and this was followed 
some years later by Ferrel’s (31, 27, 1861) very thorough 
quantitative investigation of the dynamics of the 
atmosphere. 
Am. JOUR. Ce pees SERIES, VoL. XLVI, No. 271.—Juty, 1918. 


354 LD. Page—A Century’s Progress in Physics. 


A number of individuals kept systematic records of 
meteorological observations, among whom was Loomis, 
whose storm analyses did much to settle the merits of the 
rival theories of Redfield and Espy. In studying the 
storm of 1836 (40, 34, 1841) he had drawn on the map 
lines through those points in the track of the storm where 
the barometer, at-any given hour, is lowest. While this 
method revealed the general direction in which the storm 
was progressing, it failed to give much indication of its 
size or shape. In discussing the two tornadoes of Feb- 
ruary, 1842, one of which had already been described 
in this Journal (43, 278, 1842), he adopted a new and 
more illuminating graphical method. Instead of connect- 
ing points of lowest pressure, he drew a curve through all 
points where the barometer stood at its normal level, then 
one through those points at which the pressure was 2/10 
of an inch below normal, and so on. Temperature he 
treated in much the same way, and the strength and 
direction of the wind were indicated by arrows. This 
innovation gave to his storm analyses a significance 
which had been entirely lacking in those of his predeces- 
sors, and led to the familiar systems of isobars and iso- 
therms in use on the daily charts issued by the Weather 
Bureau at the present time. Loomis advocated careful 
observations for one year at stations 50 miles apart all | 
over the United States, so that sufficient data might be 
obtained to settle once for all the law of storms. His 
efforts, seconded by those of Henry, Bache, Pierce, Abbe, 
and Lapham, led eventually to the establishment of the 
Signal Service, and the publication of daily weather 
maps according to the plan advocated thirty years 
before. These maps. afforded a basis for further 
analyses of storms, which he published in numerous 
‘‘Contributions to Meteorology’’ (8, 1, 1874, et seq.) 
between 1874 and his death in 1890. 

In addition to his work on storms, Loomis made a care- 
ful study of the earth’s magnetism (34, 290, 1838 ez seq.), 
and of the aurora borealis (28, 385, 1859 et seq.). That 
a connection existed between sunspots, aurora, and ter- 
restrial magnetism was already recognized. Loomis (50, 
153, 1870 et seq.), however, showed that the periodicity 
of the aurora borealis, as well as of excessive disturb- 
ances in the earth’s magnetic field, corresponds very 
closely with that of sunspots. 


Coe—A Century of Zoology in America. 355 


Art. XIl.—A Century of Zoology in America; by 
Westey R. Cos. 


This article is intended as a brief survey of the devel- 
opment of zoology in America, and no attempt is made 
to give a general history of the science. There are 
numerous accounts in several languages of zoological 
history in general, among them being W. A. Locy’s 
‘‘Biology and its Makers.’’ Brief outlines of the history 
of zoology may be found in many zoological and biolog- 
ical text-books. 

For the history of American zoology the reader is 
referred to Packard’s report on ‘‘A Century’s Progress 
in American Zoology,’’ published in the American Nat- 
uralist, (10, 591, 1876), to Packard’s ‘‘History of Zool- 
ogy,’’ published in volume 1 of the Standard Natural 
History (pp. lxu to Ixxi, 1885); to G. B. Goode’s 
‘‘Beginnings of Natural History in America,’ and 
‘‘Beginnings of American Science,’’? and to H. 8. Pratt’s 
Manual of the Common Invertebrate Animals (pp. 1-9), 
1916. In Binney’s ‘‘Terrestrial Air-breathing Mollusks 
of the United States’’ (1851) is a chapter on the rise of 
scientific zoology in the United States which well describes 
the zoological conditions in the early part of the century, 
while numerous monographs and papers give the history 
of the investigations on the various groups of animals 
or on special fields of study. 

Brief biographical sketches of the most distinguished 
of our older Naturalists—Wilson, Audubon, Agassiz, 
Wyman, Gray, Dana, Baird, Marsh, Cope, Goode and 
Brooks are given in ‘‘Leading American Men of Sci- 
ence,’’ edited by David Starr Jordan, 1910. 

The developmental history of zoology in America falls 
naturally into four fairly well marked periods, namely :— 
1, Period of descriptive natural history, previous to 
1847, embracing the early studies on the classification 
and habits of animals, characteristic of the zoological 
work previous to the arrival of Louis Agassiz in Amer- 
ica. 2, Period of morphology and embryology, 1847- 
1870, during which the influence of Agassiz directed the 


* Proc. Biol. Soc. Washington, 3, 35, 1886. 
*Tbid, 4, 9, 1888. Both of these papers are reprinted in Ann. Rept. 
Smithsonian Inst., 1897, U. S. Nat. Mus., Pt. 2, pp. 357-466, 1901. 


| 


356 Coe—A Century of Zoology m America. 


zoological studies toward problems concerning the rela- 
tionships of animals as indicated by their structure and 
developmental history. 3, Period of evolution, 1870- 
1890, when the principle of natural selection received 
general recognition and the zoological studies were 
largely devoted to the applications of the theory to 
all groups of animals. 4, Period of experunental biol- 
ogy, since 1890, during which time have occurred the 
remarkable advances in our knowledge of the nature of 
organisms through the application of experimental 
methods in the various branches of the modern science of 
biology. 


AMERICAN Zoouocy In 1818. 


At the beginning of the century which this volume 
commemorates, the accumulated biological knowledge of 
the world consisted mainly of what is to-day called 
descriptive natural history. The zoological treatises of 
the time were devoted to the names, distinguishing char- 
acters and habits of the species of animals and plants 
known to the naturalists of Europe either as native 
species or as the results of explorations in other parts 
of the world. This required lttle more than a super- 
ficial knowledge of their general anatomical structures. 

The naturalists of those days had no conception of the 
life within the cell which we now know to form the basis 
of all the activities of animals and plants, nor had they 
even the necessary means of studying such life. The 
compound microscope, so necessary for the study of even 
the largest of the cells of the body, was not adapted to 
such use until 1835, although the instrument was invented 
in the 17th century. With the perfection of the micro- 
scope came a period of enthusiastic study of microscopic 
organisms and microscopic structures of higher animals 
and plants. It was not until twenty years after the 
founding of this Journal that the cell theory of structure 
and function in all organisms was established by the 
discoveries of Schleiden and Schwann. 

At the beginning of the century there was great zoolog- 
ical activity in Europe, and particularly in France. But- 
fon’s great work on the Natural History of Animals had 
recently been completed, Cuvier had only one year before 
published his classic work in comparative anatomy, 
“Tie Regne Animal,’’ and Lamarck’s ‘Philosophie 


Coe—A Century of Zoology in America. 35 


Zoologique’’ had then aroused a new interest in classi- 
fication and comparative anatomy from an evolutionary 
standpoint. E. Geoffroy St.-Hilaire was at the same 
time supporting an evolutionary theory based on embry- 
onic influences resulting in sudden modifications of adult 
structure. These epoch-making discoveries and theories 
gained a considerable following in France, Germany and 
England, but seem to have had little influence on the 
zoological work of the following half century in America. 

The science of zoology as understood to-day is com- 
monly said to have been founded by Linnzus by the 
publication of the modern system of classification in the 


_ tenth edition of his ‘‘Systema Nature’’ in 1758. The 


influence of Linneus aroused an interest in biological 
studies throughout Europe and stimulated new investi- 
gations in all groups of organisms. Such studies as 
related to animals naturally followed first the classifica- 
tion and relationship of species, that is, systematic 
zoology, and then led gradually into the development of 
the different branches of the subject, as morphology, 
comparative anatomy, physiology, and embryology, 
which eventually were recognized as almost independent 
sciences. 

Of these sciences systematic zoology, which has come 
to mean the elassification, structure, relationship, distri- 
bution and habits, or natural history, is the pioneer in any 
region. ‘Thus we find in our new country at the time of 
the founding of this Journal in 1818, only sixty years 
after the publication of Linneus’ great work, the begin- 
ning of American zoology taking the form of the collec- 
tion and deseription of our native animals. 

It is true that many of our more conspicuous and easily 
collected animals were described long before the opening 
of the 19th century, but this is to be credited mainly to 
the work of European naturalists who had made expedi- 
tions to this country for the purpose of studying and 
collecting. These collections were then taken to Europe 
and the results published there. We thus find in the 12th 
edition of Linneus descriptions of over 500 American 
species, about half of which were birds. As an illustra- 
tion of the extent to which some of these works covered 
the field even in those early days may be mentioned a 
monograph in two quarto volumes with many beautifully 
colored plates on the ‘‘ Natural History of the rarer Lepi- 


ni 


358 Coe—A Century of Zoology im America. 


dopterous Insects’’ of Georgia. This was published in 
London in 1797 by. J. EK. Smith from the notes and draw- 
ings of John Abbot, one of the keenest naturalists of 
any period. | 

During the early years of the 19th century, however, 
economic conditions in our country became such as to give 
opportunity for scientific thought. Educated men then 
formed themselves into societies for the discussion of 
scientific matters. This naturally led to the establish- 
ment of publications whereby the papers presented to the 
societies could be published and made available to the 
advancement of science generally. The most influential 
of these was the Journal of the Philadelphia Academy of . 
Natural Science, which was established in 1817, and was 
devoted largely to zoological papers. The Annals of the 
New York Lyceum of Natural History date from 1823, 
and the Journal of the Boston Society of Natural History 
from 1834. The Transactions of the American Philo-. 
sophical Society in Philadelphia and the Memoirs of the 
American Academy of Arts and Sciences in Boston also 
published many zoological articles. 

In these publications and in this Journal, which was 
founded in 1818, appear the descriptions of newly dis- 
covered animal species, with observations on their habits. 

The number of investigators in this field in the first 
quarter of the 19th century was but few, and most of 
these were compelled to take for the work such time as 
they could spare from their various occupations. 

Gradually the workers became more numerous until 
about the middle of the century zoology was taught in all 
the larger colleges. The science thereby developed into 
a profession. 

For some years the studies remained largely of a sys- 
tematic nature, and embraced all groups of animals, but 
long before the close of the century the attention of the 
majority of the ever increasing group of zoologists was 
directed into more promising channels for research and 
there came the development of the sciences of compara- 
tive anatomy, physiology, embryology, experimental 
zoology, cytology, genetics, and the like, while the sys- 
tematists became specialists in the various animal groups. 

But the work in systematic zoology remains incomplete 
and many native species are still undescribed or imper- 
fectly classified. It is perhaps fortunate that a few — 


Coe—A Century of Zoology m America. 359 


faithful systematists remain at their tasks and tend to 
keep the experimentalists from the disaster which might 
well result from the unwitting confusion of their species. 


Periop oF DrscrietivE NATuRAL History.—PreEviovus To 1847. 


Of the few American naturalists whose writings were 
published toward the end of the eighteenth century and 
at the beginning of the nineteenth the names of William 
Bartram (1739-1823), Benjamin Barton (1766-1815), 
Samuel Mitchill (1764-1831), Wilham Peck (1763-1832), 
and Thomas Jefferson (1743-1826), require special men- 
tion. Bartram’s entertaining volume describing his 
travels through the Carolinas, Georgia and Florida; pub- 
lished in 1793, contains a most interesting account of the 
birds and other animals which he found. ~ 

Barton wrote many charming essays on the natural 
history of animals, but was more particularly interested 
in botany. Mitchill’s most important works include a 
history of the fishes of New York (1814), and additions to 
an edition of Bewick’s General History of Quadrupeds. 
The latter, published in 1804, contains descriptions and 
figures of some American species and is the first Ameri- 
can work onmammals. | 

Peck has the distinction of writing the first paper on 
systematic zoology published in America. This was a 
paper on new species of fishes and was printed in 1794. 
He is also well known for his work on insects and fungi. 

Jefferson in 1781 published an interesting book 
describing the natural history of Virginia, and during 
his presidency was of inestimable service to zoology 
through his support of scientific expeditions to the west- 
ern portions of the country. 

Previous to Agassiz’s introduction of laboratory meth- 
ods of study in comparative anatomy and embryology in 
1847, American naturalists generally confined their atten- 
tion to the study of the classification and habits of the 
multitude of- undescribed animals and plants of the 
region. ~ 

Such studies were naturally begun on the larger and 
more generally interesting animals such as the birds and 
mammals, and although many of these were fairly well 
described as to species before the opening of the 19th 
century, little was known of their habits. The natural 
history of our eastern birds first became well known 


360 Coe—A Century of Zoology m America. 


through the accurate illustrations and exquisitely written 
descriptions of Alexander Wilson (in 1808-1813). Bona- 
parte’s continuation of Wilson’s work was published in 
four folio volumes beginning in 1826. 

In 1828 appeared the first of Audubon’s magnificent 
folio ulustrations of our birds. These were published in 
Kingland, with later editions of smaller plates in America. 
Nuttall’s Manual of the Ornithology of the United States 
appeared in 1832-1834. 

The second work on American mammals appeared in 
the second American edition of Guthrie’s Geography, 
published in 1815. The author is supposed to have been 
George Ord, although his name does not appear. In 1825 
Harlan published his ‘‘Fauna Americana: Descriptions 
of the Mammiferous Animals inhabiting North Amer- 
ica.’? This was largely a compilation from Huropean 
writers, particularly from Demarest’s Mammalogie, and 
had little value. 

In 1826 Amos Haton published a small ‘‘Zoological 
Text-book comprising Cuvier’s four grand divisions 
of Animals: also Shaw’s improved Linnean genera, 
arranged according to the classes and orders, of Cuvier 
and Latreille. Short descriptions of some of the most 
common species are given for students’ exercises. Pre- 
pared for Rensselaer school and the popular class-room.’’ 
‘‘Four hundred and sixty-one genera are described in 
this text-book. They embrace every known species of 
the Animal Kingdom.’’ This is a compilation from 
European sources with a few American species of various 
groups included. On the other hand, Godman’s Natural 
History, in three volumes (1826-1828), was an illustrated 
and creditable work. Such was also the case with Sir 
John Richardson’s Fauna Boreali Americana of which 
the volume on quadrupeds was published in England in 
1829. The other volumes on birds, fishes and insects 
appeared between 1827 and 1836. Audubon and Bach- 
man’s beautifully illustrated ‘‘Quadrupeds of North 
America’’ was issued between 1841 and 18950. 

About 1840 several of the states inaugurated natural 
history surveys and published catalogues of the local 
faunas. The reports on the animals of Massachusetts 
and New York are the most complete zoological mono- 
graphs published in America up to that time. This is 
particularly true of DeKay’s Natural History of New 


eaten 


Coe—A Century of Zoology in America. 361 


York published between 1842 and 1844 in beautifully 
iUlustrated quarto volumes. 

The leader in the systematic studies in the early part 
of the century was Thomas Say, who published descrip- 
tions of a large number of new species of animals, par- 
ticularly reptiles, mollusks, crustacea and insects. Say’s 
conchology, printed in 1816 in Nicholson’s Cyclopedia, 
is the first American work of its kind. This was 
reprinted in 1819 under the title ‘‘Land and Fresh-water 
Shells of the United States.’? In 1824-1828 appeared 
the three volumes of Say’s American Entomology. 

The prominent position held by Say in the zoological 
work of this period is illustrated by the following para- 
sraph from Eaton’s Zoological Text-book (1826, p. 133). 
‘‘At present but a small proportion of American Ani- 
mals, excepting those of: large size, have been sought out 
.. . And though Mr. Say is doing much; without assist- 
ance, his life must be protracted to a very advanced 
period to afford him time to complete the work. But if 
every student will contribute his mite, by sending Mr. 
Say duplicates of all undescribed species, we shall prob- 


ably be in possession of a system, very nearly complete, 


in a few years.’’ How different is the attitude of the 
zoologist of to-day who sees the goal much further away 
after a century’s progress through the industry of hun- 
dreds of investigators. 

During the period of Say’s most active work he is 
reported to have ‘‘slept in the hall of the Philadelphia 
Academy of Natural Sciences, where he made his bed 
beneath the skeleton of a horse and fed himself on bread 
and milk.’’ 

Next to Say, the most active zoologist of the early part 
of the century was Charles Alexander Lesueur, who 
described and beautifully illustrated many new species of 
fishes, reptiles, and marine invertebrates. A memoir by 
George Ord, published in this Journal (8, 189, 1849), 
gives a full list of Lesueur’s papers. 

One of the most prolific writers of the period was Con- 
stantine Rafinesque, a man of great brilliancy but one 
whose imagination so often dominated his observations 
that many of his descriptions of plants and animals are 
wholly unreliable. 

Umted States Exploring Expedition.—In 1838 a fortu- 
nate circumstance occurred which eventually brought 


362 Coe—A Century of Zoology m America. 


American systematic zoology into the front ranks of the 
science. This opportunity was offered by the United 
States Exploring Expedition under the command of 
Admiral Wilkes. With James D. Dana as naturalist, the 
expedition visited Madeira, Cape Verde Islands, eastern 
i and western coasts of South America, Polynesia, Samoa, 
if Australia, New Zealand, Fiji, Hawaiian Islands, west 
| i coast of United States, Philippines, Singapore, Cape of 
i Good Hope, ete. 
it Of the extensive collections made on this four-years’ 
| cruise, Dana had devoted particular attention to the 
study of the corals and allied animals (Zoophytes) and to 
ia the crustacea. In 1846 the report on the Zoophytes was 
published in elegant folio form with colored plates. 
Six years later the first volume of the report on Crus- 
tacea appeared, with a second volume after two 
| additional years (1854). These reports describe and 
i | beautifully illustrate hundreds of new species, and 
| include the first comprehensive studies of the animals 
| forming well-known corals. They remain as the most 
4 conspicuous monuments in American invertebrate zool- 
| | ogy. Unfortunately the very limited edition makes them 
We accessible in only a few large libraries. The other, 
| equally magnificent, volumes include: Mollusca and 
ih Shells, by A. A. Gould, 1856; Herpetology, by Charles 
Girard, 1858; Mammalogy and Ornithology, by John 
| Cassin, 1858. 3 
1 Principal investigators.—Of the many writers on ani- 
| mals at this period of descriptive natural history, the fol- 
Mh lowing were prominent in their special fields of study: 
la Ayres, Lesueur, Mitchill, Storer, Linsley, Wyman, 
ii DeKay, Smith, Kirtland, Rafinesque and Haldeman 
described the fishes. : 

Green, Barton, Harlan, Le Conte, Say, and especially 
Holbrook, studied the reptiles and amphibia. Holbrook’s 
| ereat monograph of the reptiles (North American Her- 
ih petology) was published between 1834 and 1845. 
it Wilson, Audubon, Nuttall, Cooper, DeKay, Brewer, 
Le Ord, Baird, Gould, Bachman, Linsley and Fox, were 
among the numerous writers on birds. 

Godman, Ord, Richardson, Audubon, Bachman, De- 
Kay, Linsley and Harlan, published accounts of mam- 
| mals. 

On the invertebrates an important general work enti- 


Coe—A Century of Zoology in America. 363 


tled ‘‘Invertebrata of Massachusetts; Mollusca, Crus- 
tacea, Annelida and Radiata’’ was published by A. A. 
Gould in 1841, which contains all the New England 
species of these groups known to that date. 

Lea, Totten, Adams, Barnes, Gould, Binney, Conrad, 
Hildreth, Haldeman, were the principal writers on mol- 
lusks. The crustacea were studied by Say, Gould, Halde- 
man, Dana; the insects by Say, Melsheimer, Peck, 
Harris, Kirby, Herrick; the spiders by Hentz; the worms 
by Lee; the coelenterates and echinoderms by Say, Man- 
tell and others. 

The history of entomology in the United States pre- 
vious to 1846 is given by John G. Morris in this Journal 
(1, 17, 1846). In this article F. V. Melsheimer is stated 
to be the father of American Entomology, while Say was 
the most prolific writer. Say’s entomological papers, 
edited by J. L. Le Conte, were completely reprinted with 
their colored illustrations in 1859. The first economic 
treatise is that by Harris on Insects injurious to Vege- 
tation, printed in 1841. This has had many editions. 
The Entomological Society of Pennsylvania was formed 


esti wal bor S28 


The establishment of this Journal gave a further impe- 
tus to the scientific activities of Americans in furnishing 
a convenient means for publishing the results of their 
work. In the first volume of the Journal, for example, 
are two zoological articles by Say and a dozen short 
articles on various topics by Rafinesque, the latter being 
curious combinations of facts and fancy. Most of the 
zoological papers appearing in its first series of 50 vol- 
umes are characteristic of an undeveloped science in an 
undeveloped country. They deal, naturally, with obser- 
vational studies on the structure and classification of 
species discovered in a virgin field, with notes on habits 
and life histories. 

Many of the papers are purely systematic and include 
the first descriptions of numerous species of our mol- 
lusks, crustacea, insects, vertebrates and other groups. 
Of these, the writings of C. B. Adams, Barnes, A. A. 
Gould and Totten on mollusks, of J. D. Dana on corals 
and erustacea, of Harris on insects, of Harlan on reptiles, 
and of Jeffries Wyman and D. Humphreys Storer on 
fishes are representative and important. 

The progress of zoology in America during the first 


364 Coe—A Century of Zoology im America. 


twenty-eight years of the Journal’s existence, that is, up 
to the year 1846, is thus summarized by Professor Silli- 
man in the preface to vol. 50 (page ix), 1847: 


‘“Our zoology has been more fully investigated than our 
mineralogy and botany; but neither department is in danger 
of being exhausted. The interesting travels of Lewis and Clark 
have recently brought to our knowledge several plants and 
animals before unknown. Foreign naturalists are frequently 
visiting our territory; and, for the most part, convey to Europe 
the fruits of their researches, while but a small part of our 
own is examined and described by Americans: certainly this 
is little to our credit and still less to our advantage. Honorable 
exceptions to the truth of this remark are furnished by the 
exertions of some gentlemen in our principal cities, and in 
various other parts of the Union.’’ 


During these 28 years the Journal had been of great 
service to zoology not only in the publeation of the 
results of investigations but also in the review of import- 
ant zoological publications in Europe as well as in - 
America. There were also the reports of meetings of 
scientific societies. In fact all matters of zoological 
interest were brought to the attention of the Journal’s 
readers. 


Tur INFLUENCE OF Louis AGASSIZ. 


At the time of the founding of this Journal and for 
nearly thirty years thereafter descriptive natural his- 
tory constituted practically the entire work of American 
zoologists. In this respect American science was far 
behind that in Europe and particularly in France. It 
was not until the fortunate circumstances which brought 
the Swiss naturalist, Louis Agassiz, to our country in 


1846 that the modern conceptions of biological science 


were established in America. 

Agassiz was then 39 years of age and had already 
absorbed the spirit of generalization in comparative 
anatomy which dominated the work of the great leaders 
in Europe, and particularly in Paris. The influence of 
Leuckart, Tiedemann, Braun, Cuvier and Von Humboldt 
directed Agassiz’s great ability to similar investigations, 
and he was rapidly coming into prominence in the study 
of modern and fossil fishes when the opportunity to con- 
tinue his research in America was presented. On arriv- 
ing on our shores the young zoologist was so inspired 


Coe—A Century of Zoology in America. 365 


with the opportunities for his studies in the new country 
that he decided to remain. 

Bringing with him the broad conceptions of his dis- 
tinguished Huropean masters, he naturally founded a 
similar school of zoology in America. It is from this 
beginning that the present science of zoology with its 
many branches has developed. 

It must be remembered in this connection that the great 
service which Agassiz rendered to American zoology con- 
sisted mainly in making available to students in America 
the ideals and methods of Kuropean zoologists. This he 
was eminently fitted to do both because of his European 
training and because of his natural ability as an inspir- 
ing leader. 

The times in America, moreover, were fully ripe for 
the advent of European culture. There were already in 
existence natural history societies in many of our cities 
and college communities. These societies not only held 
meetings for the discussion of biological topics, but 
established museums open to the public, and to which the 
public was invited to contribute both funds and speci- 
mens. This led to a wide popular interest in natural his- 
tory. It was therefore comparatively easy for such a 
man as Agassiz to develop this favorable public attitude 
into wide popular enthusiasm. 

The American Journal of Science announces the 
expected visit of Agassiz as a most promising event for 
American Zoology (1, 451, 1846) : ‘‘ His devotion, ability, 
and zeal—his high and deserved reputation and .. . his 
amiable and conciliating character, will, without doubt, 
secure for him the cordial cooperation of our naturalists 

. nor do we entertain a doubt that we shall be hberally 
repaid by his able review and exploration of our 
country.’’ We of to-day can realize how abundantly this 
prophecy was fulfilled. | 

In the succeeding volume (2, 440, 1846) occurs the 
record of Agassiz’s arrival. ‘‘We learn with pleasure 
that he will spend several years among us, in order 
thoroughly to understand our natural history.’’ 

Immediately on reaching Boston, Agassiz began the 
publication of articles on our fauna, and the following 
year he was appointed to a professorship at Harvard. 
The Journal says (4, 449, 1847) : ‘‘Hivery scientific man in 
America will be rejoiced to hear so unexpected a piece of 


366 Coe—A Century of Zoology m America. 


good news.’’ ‘The next year the Journal (5, 139, 1848) 
records Agassiz’s lecture courses at New York and 
Charleston, his popularity with all classes of the people 
and the gift of a silver case containing $250 in half eagles 
from the students of the College of Physicians. and 
Surgeons. 

The service of Agassiz to American zoology, therefore, 


- consisted not only in the publication of the results of his 


researches and his philosophical considerations there- 
from, but also, and perhaps in even greater degree, in the 
popularization of science. In the latter direction were 
his inspiring lectures before popular audiences and the 
early publication of a zoological text-book. This book, 
published in 1848, was entitled ‘‘Principles of Zoology, 
touching the Structure, Development, Distribution and 
Natural arrangement of the races of Animals, living and 
extinct, with numerous illustrations.’’ It was written 
with the cooperation of Augustus A. Gould. The review 
of this book in the Journal (6, 151, 1848) indicates clearly 
the broad modern principles underlying the new era 
which was beginning for American zoology. 


‘‘A work emanating from so high a source as the. Principles 
of Zoology, hardly requires commendation to give it currency. 
The public have become acquainted with the eminent abilities 
of Prof. Agassiz through his lectures, and are aware of his 
vast learning, wide reach of mind, and popular mode of illus- 
trating scientific subjects . . . The volume is prepared for 
the student in zoological science; it is simple and elementary 
in style, full in its illustrations, comprehensive in its range, yet 
well considered and brought into the narrow compass requisite 
for the purpose intended.’’ 


The titles of its chapters will show how little it differs 
in general subject matter from the most recent text-book 
in biology. Chapter I, The Sphere and fundamental 
principles of Zoology; II, General Properties of Organ- 
ized Bodies; III, Organs and Functions of Animal Life; 
IV, Of Intelligence and Instinct; V, Of Motion (appa- 
ratus and modes); VI, Of Nutrition; VII, Of the Blood 
and Circulation; VIII, Of Respiration; LX, Of the Secre- 
tions; X, Embryology (Egg and its Development) ; 
XI, Peculiar Modes of Reproduction; XII, Meta- 
morphoses of Animals; XIII, Geographical Distribution © 
of Animals; XIV. Geological Succession of Animals, or 
their Distribution in Time. : 


Coe—A Century of Zoology in America. 367 


A moment’s consideration of the fact that all these 
topics are excellently treated will show how great had 
been the progress of zoology in the first half of the 19th 
century. The sixty years that have elapsed since the 
publication of this book have served principally to 
develop these separate lines of biology into special fields 
of science without reorganization of the essential princi- 
ples here recognized. This remained for many years 
the standard zoological and physiological text-book, and 
was republished in several editions here and in England. 
Another popular book is entitled ‘‘Methods of Study in 
Natural History’’ (1864). 

More than 400 books and papers were written by 
Agassiz, over a third of which were published before he 
came to America. They cover both zoological and 
geological topics, including systematic papers on living 
and fossil groups of animals, but most important of all 
are his philosophical essays on the general principles of 
biology. 

One of Agassiz’s greatest services to zoology was the 
publication of his ‘‘ Bibliographia Zoologie et Geologixe’’ 
by the Ray Society, beginning with 1848. The publica- 
tion of the Lowell lectures in Comparative Embryology 
in 1849 gave wide audience to the general principles now 
recognized in the biogenetic law of ancestral remin- 
iscence. As stated in the Journal (8, 157, 1849), the 
‘‘object of the Lectures is to demonstrate that a natural 
method of classifying the animal kingdom may be 
attained by a comparison of the changes which are passed 
through by different animals in the course of their devel- 
opment from the egg to the perfect state; the change 
they undergo being considered as a scale to appreciate 
the relative position of the species.’’ These ‘‘principles 
of classification’’ are fully elucidated in a separate pam- 
phlet, and are discussed at length in the Journal (11, 
122, 1851 ). 

One of the most interesting of Agassiz’s numerous 
philosophical essays, originally contributed to the Jour- 
nal (9, 369, 1850), discusses the ‘‘Natural Relations 
between Animals and the elements in which they live.”’ 
Another philosophical paper contributed to the Journal 
discusses the ‘‘Primitive diversity and number of Ani- 
mals in Geological times’’ (17, 309, 1854). Of this sys- 
tematic papers, those on the fishes of the Tennessee river, 


! 368 Coe—A Century of Zoology mn America. 


describing many new species, were published in the Jour- 
a. nal (17, 297, 353, 1854). 

Agassiz’s beautifully ulustrated ‘‘Contributions to the 
Natural History of the United States’? cover many sub- 


jects in morphology and embryology, which are treated 
with such thoroughness and breadth of view as to give 
them a place among the zoological classics. The Essay 
tt on Classification, the North American Testudinata, the 
ia Embryology of the turtle, and the Acalephs are the 
' special topics. These are summarized and discussed at 
| length in the Journal (25, 126, 202, 321, 34271858: " 30, 
li 142, 1860; 31, 295, 1861). 

: The volume on the ‘‘ Journey in Brazil’’ (1868) in joint 
authorship with Mrs. Agassiz is a fascinating narrative 
| _ of exploration. 

' The conceptions which Agassiz held as to the most 
| essential aim of zoological study are well illustrated 
i | in his autobiographical sketch, where he writes :° 


i ‘‘T did not then know how much more important it is to the 
La naturalist to understand the structure of a few animals, than 
| to command the whole field of scientific nomenclature. Since I 
have become a teacher, and have watched the progress of stu- 
dents, I have seen that they all begin in the same way; but 
how many have grown old in the pursuit, without ever rising 
to any higher conception of the study of’nature, spending their 
life in the determination of species, and in extending scientific 
terminology !’’ 


It is not surprising, then, that under such influence the 
older systematic studies should be replaced in large 
i | measure by those of a morphological and embryological 
ia nature. 3 

The personal influence of Agassiz is still felt in the 
lives of even the younger zoologists of the present day. 
For the investigators of the present generation are for 
if the most part indebted to one or another of Agassiz’s 
ia pupils for their guidance in zoological studies. These 
HS pupils include his son Alexander Agassiz, Allen, Brooks, 
a Clarke, Fewkes, Goode, Hyatt, Jordan, Lyman, Morse, 
He Packard, Scudder, Verrill, Wilder, and others—leaders 


ia in zoological work during the last third of the nineteenth 
| century. Through such men as these the inspiration of 


SLouis Agassiz: his Life and Correspondence, by Elizabeth Carey 
Agassiz, p. 145, 1885. : 


Coe—A Century of Zoology in America. 369 


Agassiz has been handed on in turn to their pupils and 
from them to the younger generation of zoologists. 

The essential difference between the work of Agassiz 
and that of the American zoologists who preceded him 
was in his power of broad generalizations. To him the 
organism meant a living witness of some great natural 
law, in the interpretation of which zoology was engaged. 
The organism in its structure, in its development, in its 
habits furnished links in the chain of evidence which, 
when completed, would reveal the meaning of nature. Of 
all Agassiz’s pupils, probably William K. Brooks most 
fittingly perpetuated his master’s ideals. 


PerioD oF MorpHotocy AND Empryouoey. 1847-1870. 


The new aspect of zoology which came as a result of 
the influence of Agassiz characterized the zoological work 
of the fifties and sixties, that is, until the significance 
of the natural selection theory of Darwin and Wallace 
became generally appreciated. 

The work in these years and well into the seventies was 
largely influenced by the morphological, embryological 
and systematic studies of Louis Agassiz and his school. 
The structure, development, and homologies of animals 
as indicating their relationship and position in the 
scheme of classification was prominent in the work of 
this period. The adaptations of animals to their envi- 
ronment and the application of the biogenetic law to the 
various groups of animals were also favorite subjects 
of study. : 

The most successful investigators in this period on the 
different groups of animals include:—Louis Agassiz on 
the natural history and embryology of coelenterates and 
turtles; A. Agassiz, embryology of echinoderms and 
worms; H. J. Clark, embryology of turtles and syste- 
matic papers on sponges and coelenterates; E. Desor, 
echinoderms and embryology of worms; C. Girard, 
embryology,-worms, and reptiles; J. Leidy, protozoa, 
coelenterates, worms, anatomy of mollusks; W. O. Ayres 
and T. Lyman, natural history of echinoderms; McCrady 
development of acalephs; W. Stimpson, marine inverte- 
brates; A. E. Verrill, coelenterates, echinoderms, worms ; 
A. Hyatt, evolutionary theories. bryozoa and mollusks; 
Pourtales, deep sea fauna; C. B. Adams, A. and W. G. 
Binney, Brooks, Carpenter, Conrad, Dall, Jay, Lea, 


hay 
1 Hit 


370 Coe—A Century of Zoology in America. 


S. Smith, Tryon, mollusks; E. 8. Morse, brachiopods, 
mollusks; J. D. Dana, coelenterates and crustacea; Kirt- 
land, Loew, Edwards, Hagen, Melsheimer, Packard, 
Riley, Scudder, Walsh, insects; Guill, Holbrook, Storer, 
fishes; Cope, evolutionary theories, fishes and amphibia ; 
Baird, reptiles and birds; J. A. Allen, amphibia, reptiles 
and birds; Brewer, Cassin, Coues, Lawrence, birds; 
Audubon, Bachman, Baird, Cope, Wilder, mammals. 

The progress of ornithology i in the United States pre- 
vious to 1876 is well described in a paper by J. A. Allen in 
the American Naturalist (10, 536, 1876). A sketch of the 
early history of conchology is given by A. W. Tryon in 
the Journal (33, 13, 1862). 

Jeffries Wyman was the most prominent comparative 
anatomist of this period. His work includes classic 
papers on the anatomy and embryology of fishes, 
amphibia, and reptiles. 

The fifty volumes of the second series of this Journal, 
including the years 1846 to 1870, cover approximately 
this period of morphology and embryology. During this 
period the Journal occupied a very important place in 
zoological circles, for J. D. Dana was for most of this 
period the editor-in-chief, while Louis Agassiz and Asa 
Gray were connected with it as associate editors. More- 
over, in 1864 one of the most promising of Agassiz’s 
pupils, Addison EK. Verrill, was called to Yale as pro- 
fessor of zoology and was made an associate editor 
in 1869. 

In the Journal, therefore, may be found, in its original 
articles, together with its reports of meetings and 
addresses and its reviews of literature, a fairly complete 
account of the zoological activity of the period. The 
most important zoological researches,. both in Kurope 
and America, were reviewed in the bibliographic notices. 

The most important series of zoological articles are by 
Dana himself. As his work on the zoophytes and crus- 
tacea of the U. S. Exploring Expedition continued, he 
published from time to time general summaries of his 
conclusions regarding the relationships of the various 
groups. Included among these papers are philosophical 
essays on general biological principles which must have 
had much influence on the biological studies of the time, 
and which form a basis for many of our present concepts. 

The importance of these papers warrants the list being 


Coe—A Century of Zoology m America. 371 


given in full. The titles are here in many cases abbre- 
viated and the subjects consolidated. 


General views on Classification, 1, 286, 1846. 

Zoophytes, 2, 64, 187, 1846; 3, 1, 160, 337, 1847. 

Genus Astraea, 9, 295, 1850. 

Conspectus crustaceorum, 8, 276, 424, 1849; 9, 129, 1850; 11, 
268, 1851. 

Genera of Gammaracea, 8, 135, 1849; of Cyclopacea, 1, 225, 
1846. 

Markings of Carapax of Crabs, 11, 95, 1851. 

Classification of Crustacea, 11, 993, 495 ; 12,121 (288 185k 
13, 119- 14, 297, 1852: 22, 14, 1856. 

Geographical distribution of Crustacea, 18, 314, 1854; 19, 6; 
20, 168, 349, 1855. 

Alternation of Generations in Plants and Radiata, 10, 341, 
1850. 

Parthenogenesis, 24, 399, 1857 

On Species, 24, 305, 1857. 

Classification of Mammals, 35, 65, 1863; 37, 157, 1864. 

Cephalization, 22, 14, 1856; 36, 1, 321, 440, 1863; 37, 10, 157, 
184, 1864; 41, 163, 1866; 12, 245, 1876. 

Homologies of insectean and crustacean types, 36, 233, 1863; 
47, 325, 1894. 

Origin of life, 41, 389, 1866. 

Relations of death to life in nature, 34, 316, 1862. 


Of the above, the articles on cephalization as a funda- 
mental principle in the development of the system of 
animal life have attracted much attention. The evidence 
from comparative anatomy, paleontology, and embry- 
ology alike supports the view that advance in the 
ontogenetic as well as in the phylogenetic stages is cor- 
related with the unequal growth of the cephalic region as 
compared with the rest of the body. Dana shows that 
this principle holds good for all groups of animals. His 
homologies of the limbs of arthropods and vertebrates, 
however, do not accord with more modern views. 

Other papers on the same and allied topics were pub- 
lished by Dana in other periodicals. His most conspicu- 
ous zoological works, however, are his reports on the 
Zoophytes and Crustacea of the United States Explor- 
ing Expedition, 1837-1842. The former consists of 741 
quarto pages and 61 folio plates, describing over 200 new 
species, while the Crustacea report, in two volumes, has 
1620 pages and 96 folio plates, with descriptions of about 
500 new species. Each of these remains to-day as the 


+ — 


ip! | 


372 Coe—A Century of Zoology in America. 


most important contribution to the classification of the 
respective groups. The relationships of. the species, 
genera and families were recognized with such remark- 
able judgment that Dana’s admirable system of classifi- 
cation has remained the basis for all subsequent work. 

Dana’s critical reviews (25, 202, 321, 1858) of Agassiz’s 
‘‘Contribution to the Natural History of the United 
States’’ are among the most interesting of his philosoph- 
ical discussions concerning the relationships of animals 
as revealed by their structure, their embryology, and 
their geological history. 

The remaining zoological articles in this series cover 
nearly the whole range of systematic zoology. Hspe- 
cially important are the articles by Verrill on coelenter- 
ates, echinoderms, worms and other invertebrates. 

In the years following the publication of Darwin’s 
Origin of Species in 1859 occur many articles on the 
theory of natural selection. Some of the writers attack 
the theory, while others give it more or less enthusiastic 
support. 

Experimental methods in solving biological sronleme 
were little used at this time, although a few articles of 
this nature appear in the J ournal. Of these, a paper by 
W. C. Minor (35, 35, 1863) on natural and artificial 
fission in some annelids has considerable interest to-day. 

Of the important zoological expeditions the following 
may be selected as showing their influence on American 
Zoology: 

The North Pacific Expedition, with Wiliam Stimpson 
as zoologist, returned in 1856 with much new information 
concerning the marine life of the coasts of Alaska and 
Japan and many new species of invertebrates. 

In 1867-1869 the United States Coast Survey extended 
its explorations to include the deep-sea marine life off 
the southeastern coasts and Gulf of Mexico under the 
leadership of Pourtales and Agassiz. 

The Challenger explorations (187 2-1876) added greatly 
to the knowledge of marine life off the American coast 
as well as in other parts of the world. 

The explorations of the United States Fish Commis- 
sion succeeded those of the Coast Survey in the collection 
of marine life off our coasts and in our fresh waters. 
These have continued since 1872 and have yielded most 


Coe—A Century of Zoology im America. 373 


important results from both the scientific and economic 
standpoints. 

Under the charge of Alexander Agassiz the Coast Sur- 
vey Steamer ‘‘Blake,’’ in 1877 to 1880, was engaged in 
dredging operations in three cruises to various parts of 
the Atlantic. The U. 8S. Fish Commission Steamer 
‘* Albatross,’’ also in charge of Agassiz, made three expe- 
ditions in the tropical and other parts of the Pacific in the 
years from 1891 to 1905. The study of these collections 
has added greatly to our knowledge of systematic zoology 
and geographical distribution. The reports on some of 
the groups are still in course of preparation. 


PERIOD OF EVOLUTION. 


The time from 1870 to 1890 may be appropriately called 
the period of evolution, for although it commences eleven 
years after the publication of the Origin of Species, the 
importance of the natural selection theory was but slowly 
receiving general recognition. The hesitation in accept- 
ing this theory was due in no‘small degree to the opposi- 
tion of Louis Agassiz. After the acceptance of evolution, 
although morphological and embryological studies con- 
tinued as before, they were prosecuted with reference to 
their bearing on evolutionary problems. 

Following closely the methods which had produced so 
much progress during the life of Agassiz, the field of 
_ zoology was now occupied by a new generation, among 

whom the pupils of Agassiz were the most prominent. 

The teaching of biology at this time was also strongly 
influenced by Huxley, whose methods of conducting lab- 
oratory classes for elementary students were adopted in 
most of our large schools and colleges. This placed 
biology on the same plane with chemistry as a means for 
training in laboratory methods and discipline, with the 
added advantage that the subject of biology is much more 
intimately connected with the student’s everyday life and 
affairs. | 

This increasing demand for instruction in biology and 
the consequent necessity for more teachers brought an 
increasing number of investigators into this field. New 
zoological text-books were also required. The ‘‘Stand- 
ard Natural History,’’ published in 1885, remains the 
most comprehensive general work on animals. 


ae 


iW 


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i 


Ni 


374  Coe—A Century of Zoology im America. 


Conspicuous in this period was the work of HE. D. Cope, 
best known as a paleontologist, but whose work on the 
classification of the various groups of vertebrates stands 
preeminent, and whose philosophical essays on evolution 
had much influence on the evolutionary thought of the 
time. He was a staunch supporter of the Lamarckian 
doctrine. Alpheus Hyatt also maintained this theory, 
and brought together a great accumulation of facts in its 
support. He thereby contributed largely to our knowl- 
edge of comparative anatomy and embryology. A. S. 
Packard, whose publications cover a wide range of 
topics, was best known for his text-books of zoology and 
his manuals on insects. 

W. K. Brooks was a leading morphologist and embry- 
ologist. S. F. Baird, for many years the head of the 
United States Fish Commission, was the foremost 
authority on fish and fisheries and is also noted for his 
work on reptiles, birds and mammals. The man of 
greatest influence, although by no means the greatest 
investigator, was C. O. Whitman. It is to him that we 
owe the inception of the Marine Biological Laboratory, 
the most potent influence in American zoology to-day; 
the organization of the American Morphological Society, 
the forerunner of the present American Society of Zoolo- 
gists; and the establishment of the Journal of Morph- 
ology. G. B. Goode was distinguished for his work on 
fishes and for his writings on the history of science. 

EK. L. Mark, C. S. Minot, and Alexander Agassiz were 
acknowledged leaders in their special fields of research— 
Mark in invertebrate morphology and embryology, and 
Minot in vertebrate embryology, while Alexander Agassiz 
made many important discoveries in the systematic 
zoology and embryology of marine animals, and to him 
we owe in large measure our knowledge of the life in the 
oceans of nearly all parts of the world. 

The knowledge of the representatives of the different 
divisions of the American fauna had now become suffi- 
cient to allow the publication of monographs on the vari- 
ous classes, orders and families. At this time also par- 
ticular attention was given to the marine invertebrates 
of all groups. 

Of the many investigators working on the various 
eroups of animals at this time only a few mav be men- 
tioned. The protozoa were studied by Leidy, -Clark, 


Coe—A Century of Zoology in America. 375 


Ryder, Stokes; the sponges by Clark, Hyatt; the coelen- 
terates by A. Agassiz, 8S. F. Clarke, Verrill; the echino- 
derms by A. Agassiz, Brooks, Kingsley, Fewkes, Lyman, 
Verrill; the various groups of worms by Benedict, 
Hisen, Silliman, Verrill, Webster, Whitman; the mol- 
lusks by A. and W. G. Binney, Tryon, Conrad, Dall, San- 
derson Smith, Stearns, Verrill; the Brachiopods by Dall 
and Morse; the Bryozoa by Hyatt; the crustacea by 
S. I. Smith, Harger, Hagen, Packard, Kingsley, Faxon, 
Herrick; the insects by Packard, Horn, Scudder, C. H. 
Fernald, Williston, Norton, Walsh, Fitch, J. B. Smith, 
Comstock, Howard, Riley and many others; spiders by 
Emerton, Marx, McCook; tunicates by Packard and Ver- 
rill; fishes by Baird, Bean, Cope, Gilbert, Gill, Goode, 
Jordan, Putnam; amphibians and reptiles by Cope; 
birds by Baird, Brewer, Coues, Elliott, Henshaw, Allen, 
Merriam, Brewster, Ridgway; and the mammals by 
Allen, Baird, Cope, Coues, Elliott, Merriam, Wilder. 

Interest in the evolutionary theory continued to 
increase and eventually developed into the morpholog- 
ical and embryological studies which reached their cul- 
mination between 1885 and 1890 under the guidance 
ot Whitman, Mark, Minot, Brooks, Kingsley, E. B. Wilson 
and other famous zoologists of the time. In these years 
the Journal of Morphology was established and the 
American Morphological Society was formed. 

The morphological, embryological and paleontological 
evidences of evolution as indicated by homologies, devel- 
opmental stages and adaptations were the most absorb- 
ing subjects of zoological research and discussion. 

The third series of the: Journal (1870-1895), likewise 
including fifty volumes, embraces this period of zoologi- 
eal activity in morphological and embryological studies, 
culminating with the inception of the modern experimen- 
tal methods. 

In this period also occurred the greatest progress in 
marine systematic zoology, due to the explorations of the 
United States Fish Commission off the Atlantic Coast. 
The Journal had an important share in the zoological 
development of this period also, for A. E. Verrill, who 
was now an associate editor, was in charge of the colléc- 
tions of marine invertebrates. Consequently most of the 
discoveries in this field were published in the Journal in 
numerous original contributions by Verrill and his asso- 


~~ eee en eS ee Se a De TS a Oe ee es ee ee eT) ee ee ee ee ee ee eee ee ee ee ee en a ee eee ee ee 


376 Coe—A Century of Zoology im America. 


ciates. The explorations of the U. S. Fish Commission 
Steamer ‘‘Albatross’’ are described from year to year by 
Verrill, with descriptions of the new species of inverte- 
brates discovered. 

The numerous original contributions by Verrill on 
subjects of general zoological interest as well as on those 
of a systematic nature give this third series of the Jour- 
nal much zoological importance. Verrill’s papers cover 
almost the whole field of descriptive zoology, but are 
mainly devoted to marine invertebrates. Those which 
were originally contributed to the Journal or summarized 
by him in his literature reviews include the following 
topics : 


Sponges, 16, 406, 1878. 

Coelenterates, 37, 450, 1864; 44, 125, 1867; 45, 411, 186, 46, 
143, 1868; 47, 282, 1869; 48, 116, 419, 1869; 49, 370, 1870; 3, 
187, 432, 1872; 6, 68, 1873 ; 21, 508, 1881; 6 493, 1898; 7, 41, 
143, 205, = (by 1899; 13, to. 1902. 

Echinoderms, 44, 125, 1867 ; 45, 417, 1868; 49, 93, 101, 187 (0; 
2, 430, 1871; 14 416, 1876; "49, 127, 199, 1895 ; 28, 59, 1909: 
35, 477, 1913; 37, 483, 1914; 38, 107, 1914; 39, "684, 1915. 

Worms, 50, 293, 1870; 3, 126, 1872. 

Mollusks, 49, 217, 1870; 50, 405, 1870; 3, 209, 281, 1872: 5, 
465, 1873; 7, 136. 158, 1874; 9; 123, 177, 1875; 10, 213, 1875: 
12, 236, 1876; 14, 425, 1877 ; 19, 284, 1880; 20, 250, 251, 1880: 
2, 7A, 91, 1896; 3. oil 79, 162, 355, 1897. 

Crustacea, 44, 126, 1867 ; ‘48, 944, 430, 1869; 25, 119, 534, 
1908. ; 

Ascidians, 1, 54, 98, 211, 288, 443, 1871; 20, 251, 1880. 

Dredging operations and marine fauna, 49, 129, 1870; 2, 357, 
187L: 5, 1,98, 1873-.6, 435; 1873. 7,.38, 1ale 405, 409 498" 
608, 1874; 3), 411, 1875 ; 10, 36, 196, 1875; 16, 207, 371, 1878 ; 
lve 239, 258, 309, 472, 1879 ; 18, 52, 468, 1879; 19: 17 187, 20, 
390, 1880; 29, 292, 1881: 23, 135, 216, 309, 406, 1882 ; 24, 360, 
477, 1882; 28, 213, 378, 1884; 29, 149, 1885. 

Miscellaneous, 39, i. 1865; 41, 249, 268, 1866: 44, 126, 
1867; 48, 92, 1869 ; 3, 386, 1872; 7, 134, 1847; 10, 364, 1875; 


IG, 323, 1878 ; 20, 251, 1880: 3, 132, 135, 1897; 9; S1d7 1900 : 


12,88, 1901; Ag: 327, 1902; 14, 72, 1902; 15, 332, 1903; 24, 
179, 1907; 29, 561, 1910. | 


S. I. Smith describes the motaricreieek of the crus- 
tacea (3, 401, 1872; 6, 67, 1873) species of crustacea (3, 
Shays (27, 601, 1874: 9, 476, 1875), and dredging opera- 
tions in Lake Superior (2, 373, 448,1871). In this series 
occurs also a series of papers on comparative anatomy 
and embryology from the Chesapeake Zoological Labora- 


Coe—A Century of Zoology m America. 3877 


tory in charge of W. K. Brooks. In the 39th and 40th 
volumes of the third series (1890) occur several papers 
on evolutionary topics by John T. Gulick (39, 21 ; 40, 1, 
437) which have attracted much attention. 

Before the end of this period, however, this Journal 
was relieved from the necessity of publishing zoologi- 
eal articles by the establishment of several periodicals 
devoted especially to the various fields of zoology. We 
find, therefore, but few exclusively zoological papers 
after 1885, although articles of a general biological inter- 
est and the reviews of zoological books continue. 

In the fourth series of the Journal, beginning in 1896, 
occur also a number of articles on systematic zoology by 
Verrill and others and several papers having a general 
biological interest. Brief reviews of a small number of 
zoological books are still continued, but at the present day 
the Journal, which played so important a part in the 
early development of American zoology, has been given 
over to the geological and physical sciences’ in harmony 
with the modern demand for specialization. 


PeERIoD oF EXPERIMENTAL BIOLOGY. 


Zoological studies remained in large measure observa- 
tional and comparative until about 1890 when the experi- 
mental methods of Roux, Driesch and others came into 
prominence. Interest then turned from the accumulation 
of facts to an analysis of the underlying principles of 
biological phenomena. The question now was not so 
much what the organism does as how it does what is 
observed, and this question could be answered only by 
the experimental control of the conditions. These exper- 
imental studies met with such remarkable success that in 
a few years the older morphological studies were largely 
abandoned, the Morphological Society changed its name 
to the Society of Zoologists, and in 1904 the Journal of 
Hxperimental Zoology was established. The experimen- 
tal methods were applied to all branches of biological 
science; and while it must be freely admitted that little 
progress has been made toward an understanding of the 
ultimate causes which underlie biological phenomena, a 
ereat advance has been made in the elucidation of the 
general principles involved. 

Experimental embryology, histology, regeneration, 
comparative physiology, neurology, cytology, and hered- 


ee eee eS ee ee Se Nr LS ae tale oe en LT ee ee cee en ee Mea ae TN 


378 Coe—A Century of Zoology in America. 


Sane Es have in recent years successfully adopted an experi- | 


mental aspect and have made significant progress 
thereby. Biology has now taken its place beside chem- 


_ istry and physics as an experimental science. 


The latest great advance in biology has been in the field 
of heredity. The rediscovery of the Mendelian principles 
of heredity in 1900 brought to light the most important 
generalization in biology in recent times. The new 
science of genetics is essentially the experimental study 
of heredity. | 

We are at the moment in the midst of an effort to 
establish in biology a few relatively simple laws by using 
for the purpose the vast accumulations of observational 
data gathered in past years, supplemented by such exper- 
imental data as have been provided by these more recent 
investigations. Such hypotheses as have been formu- 
lated are for the most part only tentatively held, for their 
validity is generally incapable of a critical test. But 
wherever such tests have been possible, the laws of math- 
ematics, physics and chemistry are found applicable to 
biological phenomena. 

The number of investigators has now become so great 
and their activities so prolific that the list and synopses 
of the zoological publications each year cover upwards 
of 1000 to 1500 pages in the International Catalogue of 
Scientific Literature. 

American Leadership.—During the first half of the 
century the progress of zoology in America remained dis- 
tinctly behind that of Europe. At the beginning of the 
century the science was farthest developed by the French 
and Einglish, although Linneus was a Swede and took his 
degree in Holland. Under the influence of Von Baer and 
his monumental treatise on embryology (Ueber Entwick- 
lungsgeschichte der Thiere, 1828), and supported later 
by the great physiologist, Johannes Miller, whose ‘‘ Phy- 
stologie des Menschen’’ (1846) forms the basis of modern 
physiology, the German school forged rapidly ahead and 
eventually assumed the leadership in zoology, as 1m sev- 
eral other branches of science. | 

In the latter half of the century the influence of the 
German universities dominated in a large measure the 
zoological investigations in America. The reason for 
this is partly due to the fact that many of our young 
zoologists, after finishing their college course, com- 


lerA 


Coe—A Century of Zoology in America. 379 


pleted their preparation for research by a year or more 
at a German university. The more mature zoologists, 
too, looked forward with keen anticipation to spending 
their summer vacations and sabbatical years in research 
in a German laboratory or at the famous Naples station 
in which the German influence was dominant. 

With the rise of experimental biology since 1890, how- 
ever, the American zoologists have shown so high a degree 
of originality in devising experiments, so much skill in 
performing them, and such keenness in analyzing the 
results, that they have assumed the world leadership in 
several of the special fields into which the science of 
zoology is now divided. 


BIOLOGICAL PERIODICALS. 


Perhaps in no better way can the progress of biology in 
America be illustrated than by a brief survey of the 
origin and development of the more important biological 
journals. For it will be seen that these publications have 
become more numerous and more specialized as the sci- 
ence has advanced in specialization. 

The early publications—which as is well known, treated 


mainly of the birds, mammals and other vertebrates, and . 


of insects, crustacea and shells—consisted mainly of sep- 
arate books or pamphlets, published by private subscrip- 
tion. After the establishment of the so-called Academies 
of Science, or of Arts and Sciences, toward the end of 
the 18th and in the first quarter of the 19th century, the 
reports of the meetings began to be published as period- 
ical Journals, supported by the academies. In these 
publications, and in this Journal which was founded at 
the same time, appear papers on all branches of science, 
including zoology. As soon as zoology in America 
assumed its modern aspects through the influence of 
Louis Agassiz and his followers the earliest strictly 
zoological journals were established. 

It should-be noted, however, that the journals of the 
scientific and natural history societies were more or less 
fully devoted to zoological topics according to the nature 
of the activities of the members and correspondents. 
After the establishment of the Museum of Comparative 
Zoology by Louis Agassiz came the founding in 1863 of its 
Bulletin and later its Memoirs. These publications have 
continued to the present day as a standard of excellence 


ay 


9 


380 Coe—A Century of Zoology m America. 


for the reports of zoological investigations. In con- 
nection with the systematic work on mollusks, the Amer- 
ican Journal of Conchology was established in 1865. 
The American Naturalist was founded in 1867 by four of 
Louis Agassiz’s pupils, Hyatt, Morse, Packard and Put- 
nam. It was later edited by Cope as a leading periodical 
for the publication of biological papers, particularly 
those relating to evolution, and is at present devoted to 
evolutionary topics. It is now in the 52nd volume of its 
new series. Li 
With the awakened interest in comparative anatomy 
and embryology came the need for an American journal 
which should supply a means of publication for the 
reports of researches accomplished by the increasing 
number of workers in these fields. This need was fully 
met by the establishment of the Journal of Morphology 
in 1887. This publication, now in its 30th volume, has 
equalled the best European journals in the character of 
its papers. A few years later (1891) came the Journal 
of Comparative Neurology for the publication of investi- 
gations relating to the morphology and physiology of the 
nervous system and to nervous and allied phenomena in 


_all groups of organisms. ‘Twenty-eight volumes of this 


journal have been completed. The Zoological Bulletin 
was started under the auspices of the Marine Biological 
Laboratory in 1897 for the publication of papers of a less 
extensive nature and which could be more promptly 
issued than those in the Journal of Morphology where 
elaborate plates were required. After two years the 
scope of the Bulletin was enlarged to include botanical 
and physiological subjects. The name was correspond- 
ingly changed to the Biological Bulletin. Of this import- 
ant periodical 33 volumes have been issued. 

For the publication of papers on human and compara- 
tive anatomy and embryology, the American Journal of 
Anatomy was established in 1901, and is now im its 
twenty-third volume. 

Meanwhile the trend of zoological interest was 7 ard 
topics connected with the ultimate nature of biological 
phenomena. The meaning of these phenomena could be 
determined only by the experimental method. Researches 
in this field became more prominent and the adequate 
publication of the numerous papers required the estab- 
lishment of a new journal in 1904. This was named the 


Coe—A Century of Zoology in America. B81 


Journal of Experimental Zoology. It immediately took 
its place in the front rank of American zoological period- 
icals. Twenty-four volumes have been published. 

In spite of the constantly increasing number of 
journals, the science grew faster than the means of pub- 
lication. So crowded did the American journals become 
that long delays often resulted before the results of an 
investigation could be issued. This condition was met in 
part by the sending of many papers to be published in 
European journals (a necessity most discreditable to 
American zoology) and in part by the establishment 
ef additional means of publication. Of the latter the 
Anatomical Record, now in its fourteenth volume, was 
begun in 1906 for the prompt publication of briefer 
papers on vertebrate anatomy, embryology and histology 
and for preliminary reports and notes on technique. 

During the past few years has come a great advance in 
the experimental breeding of plants and animals. Prob- 
lems in heredity and evolution have taken on a new 
interest since the importance and validity of Mendel’s 
discovery have been recognized. To meet this develop- 
ment of biology the journal Genetics was begun in 1916 
for the publication of technical papers, while the Journal 
of Heredity, modified from the American Breeders Maga- 
zine, is devoted to popular articles on animal and plant 
breeding, and Eugenics. 

On the whole, the science of zoology is now assuming 
a closer relation to practical affairs. Entomology, for 
example, is now represented by the Journal of Economic 
Entomology, of which 10 volumes have been issued since 
1907. The Journal of Animal Behavior covers another 
practical field of research. The Proceedings of the Soci- 
ety for Experimental Biology and Medicine, starting in 
1903, the American Journal of Physiology, and several 
other publications cover the physiological field. Among 
other important periodicals are the following: 


The Journal of Parasitology, established 1914, now in its 
fourth volume, is devoted to the interests of medical zoology. 
The Auk, now in the 34th volume of its new series (42d of 
old series) is the official organ of the American Ornithologists 
Union and is devoted to the dissemination of knowledge concern- 
ing bird life. The Annals of the Entomological Society of 
America, established in 1908, and now in its 10th volume, is one 
of several important entomological journals. The Nautilus, of 


382 Coe—A Century of Zoology m America. 


which 28 volumes have been issued, is one of the more successful 
journals devoted to conchology. 


In addition to these are the many volumes of syste- 
matic papers in the Proceedings of the United States 
National Museum, the practical reports in the Bulletin of 
the United States Fish Commission, the vast literature 
issued yearly by the various divisions of the United 
States Department of Agriculture, Public Health Service 
and other Governmental departments, while the list of 
publications by scientific societies, museums, and other 
institutes is constantly increasing and covers all fields of 
biological research. 

At the present time facilities for the publication of 
research on any branch of zoology are as a rule entirely 
adequate. For this highly satisfactory condition the 
science is indebted to the support given five of its most 
important journals by the Wistar Institute of Anatomy 
and Biology. 


BroLoGIcAL ASSOCIATIONS. 


An important light on the history of biology in Amer- 
ica can be thrown by a glance at the rise and development 
of societies or associations for the report and discussion 
ha of papers relating to that branch of science. In the first 
| half of the 19th century natural history societies were 


i" | formed in most cities and centers of learning. These 
ii | were very important factors in the promotion of scientific 
a research as well as in the diffusion of popular knowledge 
My ye of living things. The aims and activities of twenty-nine 
| such scientific societies, many of which were devoted 
a especially to natural history, are described in one of the 
2 early volumes of the Journal (10, 369, 1826). The Con- 
( e necticut Academy of Arts and Sciences, dating from 1799, 
HY and the Philadelphia Academy of Natural Sciences from 
|. | 1812 are among the oldest of those which still exist. 


ti Of national institutions the American Philosophical 
| Society was founded in 1743, the American Academy of 
Arts and Sciences in 1780, and the National Academy of 
Sciences in 1863. | 

ia The American Association for the Advancement of 
x Science, with its thousands of members, now has separate 
Via sections for each of the special br anches of science. This 


Coe—A Century of Zoology in America. 383 


society, organized in 1850, is said to have been the suc- 
cessor of the Association of American Geologists and 
Naturalists. This was itself a revival of the American 
Geological Society which first met at Yale in 1819. Its 
meetings have given a great support to the scientific work 
of the country. i 

In 1890, toward the end of the period in which morpho- 
logical studies were being emphasized, the professional 
zoologists of the eastern states founded the American 
Morphological Society. This association held annual 
meetings during the Christmas holidays for the presenta- 
tion of zoological papers. This name became less appro- 
priate after a few years because of the gradual decrease 
in the proportion of morphological investigations owing 
to the greater attention being directed to problems in 
experimental zoology and physiology. Consequently the 
name was changed to the American Society of Zoologists. 
To be eligible for membership in this society a person 
must be an active investigator in some branch of zoology, 
as indicated by the published results. 

The American Society of Naturalists was founded in 
1883. The original plan of the society was for the dis- 
cussion of methods of investigation, administration and 
instruction in the natural sciences, but its program is 
now entirely devoted to discussions and papers of a broad 
biological interest. It also arranges for an annual din- 
ner of the several biological societies and an address 
on some general biological topic. 

The American Association of Anatomists includes in 
its membership investigators and teachers in compara- 
tive anatomy, embryology, and histology as well as in 
human anatomy. Many professional zoologists .and 
experimental biologists present their papers before this 
society. 

These national societies have been of great service in 
fostering a high standard of zoological research. A still 
more important service, though generally less conspicu- 
ous, is rendered by the journal clubs in connection with 
all the larger zoological laboratories, and by local scien- 
tific societies which are now maintained in all the larger 
centers of learning throughout the country. There are 
also specific societies for some of the different fields of 
biological work. 


— te SS aa SS Se ee ee ee en a eS ee a re ee Pe 


en 


384 Coe—A Century of Zoology in America. 


BIoLOGICAL STATIONS. 


No insignificant factor in the development of biological 
science has been the establishment of biological stations 
where investigators, teachers and students meet in the 
Summer vacation for special studies, discussions and 
research. The most successful of these laboratories have 
been located on the seashore and here the study of marine 
life in Summer supplements the work of the school or uni- 
versity biological courses. The famous Naples Station 
was founded in 1870, and was shortly after followed by 
several others. Similar biological stations are now sup- 
ported on almost every coast in Europe and in several 
inland localities. 

The first such American school was established by 
Louis Agassiz at the island of Penikeese on the coast of 
Massachusetts in 1873, succeeding his private laboratory 
at Nahant. During that Summer more than forty stu- 
dents gained enthusiasm for the work of future years. 
Unfortunately the laboratory so auspiciously started was 
of brief duration, for the death of Agassiz occurred in 
December of the same year, and the laboratory was dis- 
continued at the end of the following Summer. Shortly 
afterward Alexander Agassiz equipped a small private 
laboratory at Newport, Rhode Island, and W. K. Brooks 
established the Chesapeake Bay Zoological Laboratory. 

At this time the United States Fish Commission was 
engaged under the direction of Spencer F. Baird in a 
survey of the marine life of the waters off the Hastern 
Coast. Between 1881 and 1886 the Commission estab- 
lished the splendidly equipped biological station at 
Woods Hole, Massachusetts. Both here and at the Fish 
Commission Laboratory at Beaufort, North Carolina, 
much work in general zoology as well as in economic prob- 
lems is accomplished. These laboratories are designed 
particularly for specialists engaged in researches con- 
nected with the work of the Fish Commission. 

A need was soon felt for a marine laboratory along 
broader lines, and one available to the students and 
teachers of the schools and colleges. To meet these 
requirements the Woods Hole Marine Biological Labora- 
tory was started in 1887, as the successor to.an earlier 
laboratory at Annisquam, and has since become a great 
Summer congress for biologists from all parts of the 
country. It is safe to say that no other institution has 


Coe—A Century of Zoology in America. 385 


been of equal service in securing for biology the high 
plane it now occupies in American science. The leading 
spirit in the establishment of this laboratory and its 
director for many years was Charles O. Whitman. 

Successful marine laboratories are located also at Cold 
Spring Harbor, Long Island; at Harpswell, Maine; and 
at Bermuda. The Carnegie Institution maintains a lab- 
oratory at Tortugas Island, Florida, for the investigation 
of tropical marine life. 

On the Pacific Coast marine laboratories are located 
at Pacific Grove and at La Jolla, California, and at Fri- 
day Harbor, Washington. Several other biological lab- 
oratories are open each Summer on our coasts, as well as 
a number of fresh-water laboratories on the interior 
lakes. There are also several mountain laboratories. 
The influence of these laboratories on American biology. 
is immeasurable. 


NaTuRAL History Museums. 


Museums of Natural History or ‘‘Cabinets of Natural 
Curios’’ as they were sometimes called, were established 
in the first half of the 19th century in connection with the 
various natural history societies. These were of much 
service in stimulating the collection of zoological ‘‘speci- 
mens’’ and in arousing a popular interest in natural 
history. 

The zoological museum of earlier days consisted of 
rows on rows of systematically arranged specimens, each 
carefully labelled with scientific name, locality, date of 
collection and donor—much like the pages of a catalogue. 
All this has now been changed; the bottles of specimens 
have been relegated to the storeroom, and the great 
plate glass cases of the modern museum represent indi- 
vidual studies in the various fields of modern zoological 
research, or individual chapters in the latest biological 
text-books. Often the talent of the artist and the skill 
of the taxidermist are cunningly combined to produce 
most realistic bits of nature. 

The United States National Museum, the American 
Museum of Natural History, the Field Columbian Museum 
and the Museum of Comparative Zoology are among the 
finest museums of the world, while many of the states, 
cities, and universities maintain public museums as a 
part of their educational systems. 


Am. Journ. Sc1.—FourtH SErRIEs, Vou. XLVI, No. 271.—Juty, 1918. 
13 


2 


386 Coe—A Century of Zoology m America. 


SYSTEMATIC ZOOLOGY AND TAXONOMY. 


The work in systematic zoology is now mainly carried 
on by specialists in relatively small groups of animals. 
This is necessitated both by the increasingly large num- 
ber of species known to science and by the completeness’ 
and exactness with which species must now be defined. 
The majority of ‘systematic workers are now connected 
with museums where the large collections furnish mate- 
rial for comparative studies. 

Prominent in this field is the United States National 
Museum, the publications of which are mainly taxonomic 
and zoogeographic, and cover every group of organism. 
The adequacy of this great museum for such studies may 
be illustrated by the collection of mammals. ‘This 
museum has the types of 1135 of the 2138 forms (includ- 
ing species and subspecies) of North American mammals 
recognized i in Miller’s list,* and less than 200 forms lack 


: representatives among the 120,000 specimens of mam- 


mals. Systematic monographs of several of the orders 
of mammals have been published. 

Systematic study of the birds has brought the number 
of species and subspecies known to inhabit North and 
Middle America to above 3000. The most comprehen- 
sive systematic treatise is the still incomplete report of 
Ridgeway® of which seven large volumes have already 
been issued. 

On the reptiles, the most complete monograph is that 
by Cope® entitled ‘‘The Crocodilians, Lizards and Snakes 
of North Ameriea.”’ 

The Amphibia have also been studied by Cope, whose 
report on the Batrachia of North America’ is the stand- 
ard taxonomic work. 

The most comprehensive systematic work on fishes is 
the Descriptive Catalogue of the Fishes of North and 
Middle America by Jordan and Hvermann.*® 

The invertebrate groups have been in part similarly 
monographed by the members of the U. S. National 
Museum staff and others, and further studies are in prog- 


4QList of North American Land Mammals in the United States National 
Museum, 1911. Bull. 79, U. S. Nat. Mus., 1912. 

' Birds of North and Middle America, Bull. 50, parts I-VII, U. 8. Nat. 
Mus., 1901-1916. 

° Report U. S. Nat. Mus. for 1898, pp. 153-1270, 1900. 

7 Bull. 34, U. S. Nat. Mus., 1889. 

® Bull. 47, parts I-IV, U. S. Nat. Mus., 1896-1900. 


Coe—A Century of Zoology in America. 387 


ress. Other taxonomic monographs published by this 
museum include the various groups of animals from 
many different parts of the world. 

A number of the larger State, municipal, and university 
museums publish bulletins on special groups represented 
in their collections as well as articles of general zoological 
interest. 

Expeditions, subsidized by museum and private funds, 
are from time to time sent to various parts of the world 
and their results are often published in sumptuous 
manner. 

The total number of living species of animals is 
unknown, but considering that about a quarter of a mil- 
hon new species have been described during the past 
thirty years, it is probable that several million species are 
in existence to-day. More than half a million have been 
described. These are probably but a small fraction of 
the number that have existed in past geological ages. 

Thus, in spite of all the work that has been done in sys- 
tematic zoology and as the number of known species con- 
tinues to increase, there still remain many groups of 
animals, some of which are by no means rare or minute, 
in which probably only a small proportion of the species 
are as yet capable of identification. 

It is only since the publication of Ward and Whipple’s 
‘‘Fresh-water Biology’’ within the past year that the 
amateur zoologist could hope to find even the names of 
all the organisms to be found in a single pool of water. 

During the past few years there has been a tendency on 
the part of some of our biologists engaged in experimen- 
tal work to disparage the studies of the systematists. It 
must be granted, however, that both lines of work are 
essential to the sound development of zoological science, 
for experimental investigations in which the accurate 
diagnosis of species is ignored always result in confusion. 

Ecology—The marvelous modifications in structure 
and instincts by which the various animals are adapted 
to their surroundings now forms a special topic in biolog- 
ical research and one of the most fascinating. The adap- 
tations in habitat, time, behavior, appearance and even 
in structure are found capable of a certain individual 
modification when studied experimentally. 

Zoogeography.—Closely associated with systematic 
zoology, and indeed a part of the subject in its broader 


388 Coe—A Century of Zoology in America. 


sense, is the study of the geographical distribution of 
animal species and larger groups. 

Paleontology.—The geological succession of organisms 
embraces a field where zoologist and geologist meet. 
Most of the studies in this subject, however, have been 
made by geologists. 


BIOMETRY. 


Since Darwin’s theory of evolution postulated the 
origin of new species by means of natural selection, it 
was obviously necessary in order to apply a critical test 
to determine the precise limits of a species. It was, 
therefore, proposed to subject a given species to a strict 
examination by the application of statistical methods to 
determine the range of variation of its members and the 
extent to which the species intergrades with others. 
Other problems, particularly those concerning heredity, 
were treated in similar manner. This branch of biolog- 
ical science was particularly developed by the English 
School, led by Sir Francis Galton, followed by Karl 
Pearson and William Bateson. 

In America the methods of biometry have been utilized 
extensively by Charles B. Davenport, Raymond Pearl, H. 
S. Jennings and others in the solution of problems in 
genetics and evolution. Their work shows the great 
iy value of critical statistical analysis in the interpretation 
" of biological data. A thorough training in mathematics 
; 


1] is now found to be hardly less important for the biologist 

| than is a knowledge of physics and chemistry, for the 

a science of biometry has become one of the most important 

; adjuncts to the study of genetics. 

iq 

hy CoMPARATIVE ANATOMY AND EMBRYOLOGY. 

¢ Comparative Anatomy.—Upon the foundations laid 
| | down by Cuvier a century ago the present elaborate 
o | structure of comparative anatomy of animals, both verte- 

iN brate and invertebrate, has been developed. Vast as is 


i the present accumulation of facts and theories many 
ie important problems still await their solution. Jeffries 
ne Wyman was long a leader in this field, where many 


i workers are now engaged. 
ih Embryology—The embryological studies, so bril- 
ia liantly begun by Von Baer early in the nineteenth cen- 


ie tury, are stillin progress. They have now been entended 


Coe—A Century of Zoology im America. 389 


to the groups more difficult of investigation and into the 
earliest stages of fertilization and implantation in the 
mammals. Artificial cultural methods have yielded 
important results. Louis and Alexander Agassiz, Mark, 
Minot, Brooks, Whitman, Conklin and EK. B. Wilson have 
taken prominent parts in this work. 

In the early nineties embryological studies were 
directed to the arrangement of cells in the dividing ege, 
and there was much discussion of ‘‘cell lineage” in 
development. Valuable as were these studies they threw 
comparatively little light on the general problems of 
evolution. 

Ezpervmental Embryology—A wore fertile field, 
developed at the same period and a little later, was found 
in experimental embryology. The discoveries made by 
Driesch and others in shaking apart the cells of the divid- 
ing egg or by destroying one or more of these cells gave 
a new insight into the potency of cells for compensatory 
and regenerative processes. These studies attracted 
many able investigators, who made still further advance 
by subjecting the germ cells, developing eggs, embryos, 
and developing organs to a great variety of artificial con- 
ditions. 

Artifiaal Parthenogenesis.—Another question concerns 
the nature of the process of fertilization and the agencies 
which cause the fertilized egg to develop into an embryo. 
In 1899 Jacques Loeb succeeded in causing development 
in unfertilized sea-urchin eggs by subjecting them to con- 
centrated sea water for a period and then returning them 
to their normal environment. ‘To this promising field of 
experimental work came many of the foremost biologists 
both in America and Europe. It was soon found that 
the eges of most groups of animals except the higher 
vertebrates could be made to develop into more or less 
perfect embryos and larval forms by treatment with a 
ereat variety of chemical substances, by increased tem- 
perature, by mechanical stimuli and by other means. 
This artificial parthenogenesis, as it is called, has also 
been successful in plants (Fucus), and recently Loeb has 
reared several frogs to. sexual maturity by merely 
puncturing with a sharp needle the eggs from which they 
were derived. Loeb, then, maintains that ‘‘the egg is the 
future embryo and animal; and that the spermatozoon, 


390 Coe—A Century of Zoology m America. 


aside from its activating effect, only transmits Mendelian 
characters to the egg.’’® 

Further experimental analyses of the nature of the fer- 
tilization mechanism have recently been made by Mor- 
ean, Conklin, F. R. Lillie, and others. 

Germinal Locahization.—The question as to whether the 
egg contains localized organ-forming substances has been 
studied experimentally particularly by means of the cen- 
trifuge. The results indicate that neither of the older 
opposing theories of ‘‘performation’’ or ‘‘epigenesis’’ 1s 
applicable to all eggs, but that in certain organisms the 
eggs possess a well-marked differentiation while in 
others each part of the egg is essentially, although prob- 
ably not absolutely, equipotential. 

The Germplasm Cycle-—Since Weismann’s postula- 
tion of the independence of soma and germplasm in 1889 
many attempts have been made to trace the path of the 
hereditary substance from one generation to the next. 
A recent book by Hegner!® summarizes the success 
attained in various groups of animals. 


CyToLoGy. 


Another important field of investigation which has 
attracted many workers is that which pertains to the hfe 
of the cell—the science of cytology. Although the cell- 
theory was established as early as 1839, little advance 
was made in this subject in America before 1880. Since 
that time, however, Americans have been so successful in 
cytological discoveries that they are now among the 
world’s leaders in this field. 

These studies have been followed along both desecrip- 
tive and experimental lines. The most prominent of the 
early workers in this field are E. L. Mark and EK. B. Wil- 
son. Mark’s description of the maturation, fecundation, 
and segmentation of the egg is the most accurate and 
complete of the early cytological studies. Wilson’s 
discoveries concerning the details of fertilization and 
his ‘‘Atlas of Fertilization and Karyokinesis,’’ pub- 
lished in 1895, have now become classic. Wilson, too, 
has published the only American text-book on cytology,"? 
and has more recently taken the lead in studies concern- 


° J. Loeb, The Organism as a Whole, p. 126, 1916. 
1° The Germ-cell Cycle in Animals, 1914. 
“1 The Cell in Development and Inheritance, 1896; second edition, 1900. 


Coe—A Century of Zoology in America. 391 


ing the relation between the chromosomes and sex. 
Besides Wilson, Montgomery, Mark, McClung, Morgan, 
Miss Stevens, Conklin and their associates and students 
have now furnished conclusive evidence that the sex of 
an organism is determined by, or associated with, the 
nuclear constitution of the fertilized egg. This consti- 
tution is moreover shown to be dependent upon the chro- 
mosomes received from the germ cells. 

This explanation is in strict accordance with the results 
of experimental breeding. It is also quite in harmony 
with the Mendelian law of inheritance, and in fact forms 
one of the strongest supports for the view that all Men- 
delian factors are resident in the chromosomes. Recent 
work has also discovered the mechanism which governs 
the compleated conditions of sex which occur in those 
animals which exhibit alternating sexual and partheno- 
genetic generations. These remarkable processes are in 
all cases found to depend upon a definite distribution of 
the chromosomes. 

Other recent experimental work has shown that while 
the sex is thus normally determined in the fertilized egg, 
it is in Some animals not irrevocably fixed, and the normal 
effect of the sex chromosomes may be inhibited by 
abnormal conditions in the developing embryo, as is 
demonstrated by the recent work of Lillie and others. 

The cytological basis for Mendelian inheritance has 
been very extensively studied by Morgan and his pupils 
in connection with their work on inheritance in the com- 
mon fruit fly Drosophila. The evidence supports Weis- 
mann’s earlier hypothesis that the chromosomes are the 
bearers of the heritable factors, and that these are 
arranged in a series in the different chromosomes. This 
theory is shown to be in such strict accord with both the 
cytological studies and the results of experimental breed- 
ing that Morgan has ventured to indicate definite points 
in particular chromosomes as the loci of definite heri- 
table factors, or genes. 

Confirmation of this view is furnished by the behavior 
of the so-called sex-linked characters, the genes for which 
are situated in the same chromosome as that which 
earries the sex factor. Many ingenious breeding experi- 
ments indicate further that all the hereditary characters 
in Drosophila are borne in four great linkage groups 


392 Coe—A Century of Zoology m America. 


corresponding with the four pairs of chromosomes which 
the cells of this fly possess. 


COMPARATIVE PHYSIOLOGY. 


None of the experimental fields has been of greater 
importance in zoological progress than that which con- 
cerns the functions of the various organs. Without this 
companion science morphology and comparative anatomy 
would have become unintelligible. American investiga- 
tors, among whom G. H. Parker stands prominent, have 
taken a leading part in this field also. 

Neurology.—The physiological analysis of the com- 
ponents of the nervous system, both in vertebrates and 
invertebrates, is another important branch of experimen- 
tal biology. The 28 volumes of the Journal of Compara- 
tive Neurology attest the large influence that American 
investigators have had in the development of this science. 

Regeneration.—Eixperimental studies on the powers 
of regeneration in plants and animals have been made 
from the earliest times. During the past few years, how- 
ever, there has been made a concerted attempt to analyze 
the factors which determine the amount and rate of 
regeneration. Much progress has been made toward the 
postulation of definite laws applicable to the regenerative 
processes of the parts of each organism. The critical 
analyses of Child have been particularly stimulating. 

Tissue Culture.—Another line of experimental work 
which has been developed within the past few years by 
Harrison, Carrell, and others is the culture of body 
tissues in artificial media. These experiments have 
included the cultivation in tubes or on glass slides of the 
various tissues of numerous species of animals. They 
have yielded much information regarding the structure, 
erowth and multiplication of cells, the formation of tis- 
sues, and the healing of wounds. 

Transplantation and Grafting—Closely associated 
experiments consist in the transplantation of organs or 
other portions of the body to abnormal positions, to the 
bodies of other animals of the same species or of other 
species. In this way much has been learned about the 
potentiality of organs for self-differentiation, for regula- 
tion, for regeneration and for compensatory adaptations. 
The experiments have shown, further, the independence 
of soma and germplasm and have revealed the nature of 
certain organs whose functions were previously obscure. 


Coe—A Century of Zoology in America. 393 


Tropisms and Instincts.—Another field of experimen- 
tal biology concerns the analysis of behavior of organ- 
isms in response to various forms of stimuli. These 
studies are being prosecuted on all groups of organisms, 
including the larval stages of many animals, and are 
yielding most remarkable results. The success in this 
field of research is largely due to stimulating influence of 
Jacques Loeb, Parker, Jennings, and their co-workers. 

Biological Chemistry.—Still another experimental field 
which has developed into one of the most important of 
the biological sciences relates to the fundamental chem- 
ical and physical changes which underlie all organic phe- 
nomena. A knowledge of both physiological and physi- 
cal chemistry is to-day essential for all advanced 
biological work. The peculiar nature of life itself, of 
growth, disease, old-age, degeneration, death and dissolu- 
tion are presumably only manifestations of chemical and 
physical laws. The ultimate goal of all experimental 
biology, therefore, will be reached only when the basic 
physico-chemical properties of life are understood. At 
that time only will the perennial controversy between 
vitalism and mechanism be ended. 


Economic Zoouoey. 


A moment’s reflection will show that economic 
biology is the most essential of all sciences to the human 
welfare and progress. For man’s relation to his envi- 
ronment is such that the penalty for ignorance or neg- 
lect of the biological principles involved in the struggle 
for existence quickly overwhelms him with a horde of 
parasites or other enemies. 

It is only by the intelligent application of biological 
knowledge that our food supplies, our forests, our domes- 
ticated animals and our bodies can be protected from the 
ever ravenous organisms which surround us. 

The losses to food supplies and other products by 
insects alone amounts to 100 millions of dollars a month 
in the United States. And the parasites cause losses in 
sickness and premature deaths each year of many mil- 
lions more. Then there are the destructive rodents and 
other animals which add largely to our burdens of sup- 
port. These enemies next to wars and fungi are the most 
destructive agencies on earth. Could they but be elim- 


394 Coe—A Century of Zoology in America. 


inated man’s struggle against opposing forces would be 
in large measure overcome. The results of recent work 
in economic zoology, both in regard to the destruction of 
enemies and protection of useful mammals, birds and 
fishes, furnish a bright outlook for the future. 

Protozoology.—Fartly as an experimental field for the 
solution of general biological problems and _ partly 
because of its practical applications the study of protozoa 
has now developed into a special science. 

The results of the investigations of Calkins, Woodruff, 
Jennings and others have greatly supplemented our 
understanding of the signification of such important 
biological phenomena as reproduction, sexual differen- 
tiation, conjugation, tropisms, and metabolism. 

From an economic standpoint the protozoa have 
recently been shown to be of the greatest importance 
because of the human and animal diseases for which they 
are responsible. 

Parasitology.—The animal parasites of man, domesti- 
cated animals and plants include numerous species of 
protozoa, worms, and insects. Together with the bac- 
teria and a few higher fungi they cause all communicable 
diseases. When we consider that not only our health 
but also our entire food supply is dependent upon the 
elimination of these organisms we must admit that para- 
sitology is the most important economically of all the 
sciences. 

The reports of the investigations of Stiles and his 
associates in the Hygienic Laboratory and of Ransom 
and his staff in the Bureau of Animal Industry are widely 
distributed by the federal government. The systematic 
studies so ably begun by Joseph Leidy in the middle of 


- the last century have been continued by Ward, Linton, 


Pratt, Curtis and others on the parasites of many groups 
of animals. 

Economic Entomology.—Another extremely important 
biological science, the practical applications of which are 
second only to those of parasitology in importance, is 
entomology. In the last few years economic entomology — 
has exceeded any of the other branches of biology in the 
number of its investigators. The American Association 
of Economic Entomologists has a membership of about 
five hundred. The work of most of these is supported by 
appropriations from the State and federal governments, 


Coe—A Century of Zoology in America. 395 


and the results of their investigations are widely 
published. 

It is now well known that some of the protozoon par- 
asites are conveyed from man to man only through 
the bites of insects. The local eradication of several 
of our most fatal diseases has recently been brought 
about by the application of measures to destroy such 
insects. This is the greatest triumph of economic 
zoology. i 

Economic Ormthology and Mammalogy.—tIn addition 
to the local bird clubs and the American Ornithologists 
Union for the study and preservation of bird and mam- 
mal life, the Bureau of Biological Survey has for some 
years conducted investigations on the economic import- 
ance of the various species. The publications of this 
Bureau are of great value both in determining the 
economic status of our birds and mammals, and also in 
recommending means for the protection of the beneficial 
species and the destruction of the injurious. Several of 
the States issue similar publications. 

Economic Ichthyology——The U. 8S. Fish Commission 
has for many years been actively engaged in investiga- 
tions on the food fishes, including methods for increasing 
the food supply by suitable protection and artificial 
propagation. The work includes also edible and other- 
wise useful mollusks and crustacea. Their marine and 
fresh-water laboratories have also been of great service 
to general biological science. 


GENETICS. 


One of the most interesting chapters in biology relates 
to the development of the modern science of heredity, 
or genetics. 

Previous to the year 1900, when the Mendelian princi- 
ple of inheritance was re-discovered, the relative import- 
ance of heredity and of environment in the development 
of an organism was little understood. It is true that 
Weismann had insisted on the independence of soma and 
germplasm some years earler (1883), but the body of 
the individual was still generally considered the key to 
its inheritance. 

The recognition of the general application of Mendel’s 
discovery gave a great impetus to experimental breeding 
both in plants and animals. While heretofore it had been 


396 Coe—A Century of Zoology im America. 


necessary to depend upon the somatic characters as evi- 
dence of the hereditary constitution of an individual, it 
now became possible, knowing the hereditary constitution 
of the parents of any pair of individuals, to predict with 
almost mathematical certainty the characters of their 
possible offspring. 

In general, the laws of possible chance combinations of 
any group of characters determine the probability of any 
particular offspring possessing one or many of those 
characters. The’ physical basis for such Mendelian 
inheritance is evidently the chance combinations of 
chromosomes which result from the processes of matura- 
tion and union of the germ cells. 

Certain limitations to the law are met with because 
the relatively small number of chromosomes involves 
linkage of genes, because of the occasional interchange of 
groups of genes between homologous chromosomes, and 
because the relative activity or potency of any partic- 
ular gene may differ in different races, and, finally, 
because the normal activity of any given gene may be 
modified or inhibited by the action of other genes. It is— 
by no means certain, however, that all inheritance is 
Mendelian, for there still remains much evidence that the 
hereditary basis of certain characters may be resident in 
the cytoplasm, rather than in the chromosomes. A 
recent book by Morgan, Sturtevant, Muller and Bridges 
(1915), entitled ‘‘the mechanism of Mendelian heredity’’ 
gives the cytological explanation of Mendelian inher- 
itance. 

Americans have from the first taken a ieuaines part in 
this field of research and have been quick to recognize its 
practical applications to the improvement of breeds in 
both animals and plants. This prominent position is 
largely due to the experimental work of Castle, Daven- 
port, Morgan, Jennings, Pearl, and their co-workers on 
animals and that of East, Emerson, Davis, Hayes and 
Shull on plants. 

The geneticist now realizes that the appearance of the 
body (phenotype) gives but little clue to the inheritance 
(genotype). That two white flowers produce only pur- 
ple offspring, or two white fowls only deeply colored 
chickens, or that a pair of guinea pigs, one of which is 
black and the other w hite, “have only gray agouti off- 
spring, while other appar ently similar white flowers or 


————— 


Fa 
= 


= 


Coe—A Century of Zoology in America. B97 


white animals produce offspring like themselves, is now 
readily ,comprehensible and mathematically predictable. 

‘The most important application of our newly acquired 
knowledge of inheritance is in the improvement of the 
human race. The wonderful opportunity in this direc- 
tion must be apparent to all. The welfare of humanity 
depends upon the immediate adoption of eugenic princi- 
ples. The Eugenics Record Office has secured many of 
the essential data. 

With the destruction of the world’s best germ plasm 
at a rate never equalled before, the outlook for the future 
race would be appalling were it not for the hope that with 
the advent of a righteous peace will come a realization of 
the necessity of applying these new biological discoveries 
to improving the races of men. That the discoveries 
have been made too late in the world’s history to be of 
such use to humanity must not be thought possible. 


EVOLUTION. 


Previous to the publication of Darwin’s Origin of Spe- 
cies in 1859, American zoologists were generally inclined 
toward special creation, in spite of the evidences for 
evolution which had been presented by Erasmus Darwin, 
Lamarck, and Geoffroy St. Hilaire. Indeed this attitude 
of mind continued for some years after the publication of 
the natural selection theory of Darwin and Wallace. 
This was in part due to the powerful influence of Louis 
Agassiz who bitterly opposed the Darwinian theory. As 
late as 1876, J. D. Dana only half-heartedly accepted it 
as indicated in his last essay on ‘‘Cephalization a funda- 
mental principle in the development of animal life’’ (12, 
245-251, 1876). He says: 


‘The method by repeated creations through communications 
of Divine power to nature should be subordinated, as much as 
any other, to molecular law and all laws of growth; for molecu- 
lar law is the profoundest expression of the Divine will, the very 
essence of nature; and no department of nature is without its - 
appointed law of development. But the present state of science 
favors the view of ‘progress through the derivation of species 
from species, with few occasions for Divine intervention. For 
the development of Man, gifted with high reason and will, and 
thus made a power above Nature, there was required, as Wallace 
has urged, the special art of a Being above Nature, whose su- 
preme will is not only the source of natural law, but the working 
force of Nature herself,’ and this I still hold.’’ He further 
explains that cephalization ‘‘is not at all at variance with 


398 Coe—A Century of Zoology m America. 


Darwinism.’’ In his later years he gave the theory his complete, 
though reluctant, acceptance. 


A modified Lamarckian doctrine was widely end 
in the last quarter of the century, due largely to the 
influence of Cope, Hyatt and Packard. The inheritance 
of ‘acquired characters’’ demanded by this theory seems 
incompatible with the discoveries of recent times, so that 
‘‘today the theory has few followers amongst trained 
investigators, but it still has a popular vogue that is wide- 
spread and vociferous.’’!? 

The origin of new varieties and species by accidental 
modifications of the germplasm is now the most widely 
accepted theory of evolution. 

Some of the most important discoveries regarding the 
origin of new forms have been recently made by Morgan 
and his pupils. From a stock of the common fruit fly 
(Drosophila ampelopila) more than 125 new types have 
arisen within six years. Hach of these types breeds true. 
‘‘HMach has arisen independently and suddenly. Every 
part of the body has been affected by one or another of 
these mutations.’’ To arrange these mutations arbi- 
trarily into graded series would give the impression of an 
evolutionary series, but this is directly contrary to the 
known facts concerning their origin, for each mutation 
‘‘originated independently from the wild type.’’ ‘‘HKivo- 
lution has taken place by the incorporation into the race 
of those mutations that are beneficial to the life and 
reproduction of the individual.’’ This evolutionary 
process is usually accompanied by the elimination of 
those forms which have remained stable or which have 
developed adverse mutations. 

A question that is being vigorously debated at this 
time concerns the possible effects of selection on the 
hereditary factors. Are the genes fixed both qualita- 
tively and quantitatively or does a given gene vary in 
potency under different conditions and in different indi- 
viduals? In the former case selection can only separate 
the existing genes into separate pure strains. But if the 
gene be quantitatively variable, then selection will result 
in the establishment of new types. 

Castle has long stoutly maintained the effect of such 
selection, and his forces have recently been augmented bv 
Jennings. The experimental work now in ea will 
doubtless yield a decisive answer. 

72 Morgan, T. H. A eritique of the theory, of evolution, p. 32, 1916. 


Goodale—Development of Botany Since 1818. 399 


Art. XII1.—The Development of Botany as shown in this 
Journal; by Grorce L. Goopate. 


“Our Botany, vt 1s true, has been extensively and 
successfully wmnvestigated, but this field 1s stall rich, and 
rewards every new research with some interesting dis- 
covery.”’ 


Such are the words with which the sagacious and far- 
sighted founder of the American Journal of Science and 
Arts, in his general introduction to the first volume, 
alludes to the study of plants. It is plain that the editor, 
embarking on'this new enterprise, appreciated the attrac- 
tions of this inviting field and sympathetically recognized 
the good work which was being done in it. It is not sur- 
prising, therefore, to find that he welcomed to the pages 
of his initial number contributions to botany. 

Early Botanical Works.—The collections of dried and 
living North American plants, which had been carried 
from time to time to botanists in Europe, had been 
eagerly studied, and the results had been published in 
accessible treatises. Besides these general treatises, 
there had been issued certain works, wholly devoted to 
the American Flora. Among these latter may be men- 
tioned Pursh’s Flora (1814) and Nuttall’s Genera (1818). 
There were also a few works which were rather popular 
in their character, such as Amos Eaton’s Manual of Bot- 
any for North America (1817), and Bigelow’s Collection 
of the Plants of Boston and environs (1814). These 
handbooks were convenient, and possessed the charm of 
not being exhaustive; consequently a botanist, whether 
professional or amateur, was stimulated to feel that he 
had a good chance of enriching the list of species and 
adding to the next edition. 


THe EARLY YEARS OF BOTANY IN THE JOURNAL. 


At that time, the botanists had no journal in this 
country devoted to their science. Here and there they 
found opportunity for publishing their discoveries in 
some medical periodical or in a local newspaper. Hence 
American botanists availed themselves of the welcome 
extended by Silliman to botanical contributors to place 
their results on record in a magazine devoted to science 
in its wide sense. Specialization and subdivision of 


400  Goodale—Development of Botany Since 1818. 


science had not then begun to dissociate allied subjects, 
and, consequently, botanists felt that they would be at 
home in this journal conducted by a chemist. Botanists 
responded promptly to this invitation with interesting 
contributions. 

It is well to remember that the appliances at the com- 
mand of naturalists at the date when the Journal began 
its service, were imperfect and inadequate. The botanist 
did not possess a convenient achromatic microscope, and 
he was not in possession of the chemical aids now deemed 
necessary in even the simplest research. Hence, atten- 
tion was given almost wholly to such matters as the 
forms of plants and the more obvious phenomena of 
plant-life. In view of the poverty of instrumental aids 
in research, the results attained must be regarded as sur- 
prising. 

In the very first volume of the Journal, bearing the date 
of 1818, there are descriptions of four new genera and of 
four new species of plants; certainly a large share to 
give to systematic botany. Besides these articles, there 
are some instructive notes concerning a few plants, which 
up to that time had been imperfectly understood. There 
are four Floral Calendars which give details in regard 
to the blossoming and the fruiting of plants in limited 
districts, a botanical subject of some importance but 
likely to become tedious in the long run. Just here, the 
skill of the editor in limiting undesirable contributions is 
shown by his tactful remark designed to soothe the feel- 
ings of a prolix writer whose too long list of plants in a 
floral calendar he had editorially cut down to reasonable 
limits. The editor remarks, ‘‘such extended observa- 
tions are desirable, but it may not always be convenient 
to insert very voluminous details of daily floral oceur- 
rence.’’ It is convenient to consider by themselves some 
of the botanical contributions published in the first series 
of volumes of the Journal during a period of twenty 
years, the period before Asa Gray became actively and 
constantly associated with the Journal. 

In systematic and geographical botany one finds com- 
munications from Douglass and Torrey (4, 56, 1822) 
on the plants of what was then the North-west; Lewis C. 
Beck (10, 257, 1826; 11,-167, 1826; 14, 112, 1828) contri- 
buted valuable papers on the botany of Illinois and Mis- 
souri; there is a literal translation by Dr. Ruschenberger 


Goodale—Development of Botany Since 1818. 401 


(19, 63, 299, 1831; 20, 248, 1831; 23, 78, 250, 1833) of a 
very long list of the plants of Chili; Wolle and Huebener 
(37, 310, 1839) gave an annotated catalogue of botanical 
specimens collected in Pennsylvania; Tuckerman (45, 27, 
1843) presented communications in regard to numerous 
species which he had examined critically; Darlington 
(41, 365, 1841) published his lecture on grasses; Asa Gray 
(40, 1, 1841) gave an instructive account of European | 
herbaria visited by him, and he contributed also a charm- 
ing account (42, 1, 1842) of a botanical journey to the 
mountains of North Carolina. The most extensive series 
of botanical communication at this time was the Caricog- 
raphy by Professor Dewey of Willams College, pre- 
sented in many numbers of the Journal; the first of these 
in 7, pp. 264-278, 1824. There were also descriptions of 
certain new genera, and species, and critical studies in 
synonyms. 

Cryptogamic botany is represented in the first series 
of volumes of the Journal by L. C. Beck’s (15, 287, 1829) 
study of ferns and mosses, by Bailey’s (35, 113, 1839) 
histology of the vascular system of ferns, by Fries’ Sys- 
tema mycologicum (12, 235, 1829), and by De Schweinitz 
(9, 397, 1825) and Halsey, who had in hand a cryptogamic 
manual. There are two important papers by Alexander 
Braun, translated by Dr. George Engelmann, one on the 
Equisetacee of North America (46, 81, 1844) and the 
other on the Characee (46, 92, 1844). 

Vegetable paleontology had begun to attract attention 
in many places in this country, and therefore the trans- 
lated contributions by Brongniart on fossil plants were 
given space in the Journal. Plant-physiology received 
a good share of attention either in short notices or in 
longer articles. Such titles appear as, the respiration of 
plants, the circulation of sap, the excrementitious matter 
thrown off by plants, the effects of certain gases and 
poisons on plants, and the relations of plants to different 
colored light. One of the most important of the notes 
is that in which is described the discovery by Robert 
Brown (19, 393, 1831) of the constant movement of 
minute particles suspended in a liquid, first detected by 
him in the fovilla of pollen grains, and now known as the 
Brownian (or Brunonian) movement. The heading 
under which this note appears is of interest, ‘‘The motion 
of living particles in all kinds of matter.”’ 


402. Goodale—Development of Botany Since 1818. 


One side of botany touches agriculture and economics. 
That side was represented even in the first volume of the 
Journal by a study of ‘‘the comparative quantity of nutri- 
tious matter which may be obtained from an acre of land 
when cultivated with potatoes or wheat.’’ Succeeding 
volumes in this series likewise present phases which are 
of special interest regarded from the point of view of 
economics; for example, those which treat of rotation of 
crops and of enriching the soil. Probably the economic 
paper which may be regarded as the most important, in 
fact epoch-making, is the full account of the invention by 
Appert of a method for preserving food indefinitely 
(13, 163, 1828). We all know that Appert’s process has 
revolutionized the preservation of foods, and in its mod- 
ern modification underlies the vast industry of canned 
fruits, vegetables and so on. There are suggestions, 
also, as to the utilization of new foods, or of old foods in 
a new way, which resemble the suggestions made in these 
days of food conservation. For example, it is shown 
that flour can be made from leguminous seeds by steam- 
ing and subsequent drying, and pulverizing. There are 
excellent hints as to the best ways of preparing and using 
potatoes, and also for preserving them underground, 
where they will remain good for a year or two. It is 
shown that potato flour can be made into excellent bread. 
Another method of making bread, namely from wood, is 
described, but it does not seem quite so practicable. 
There are interesting notes on the sugar-beet as a source 
of sugar, and here appears one of the earliest accounts of 
the Assam tea-plant, which was destined to revolutionize 
the tea industry throughout the world. Cordage and tex- 
tile fibers of bark and of wood should be utilized in the 
manufacture of paper. In fact one comes upon many 
such surprises in economic botany as the earlier volumes 
of the Journal are carefully examined. 

Karly numbers of the Journal present with suff- 
cient fulness accounts of the remarkable discovery by 
Daguerre and others of a process for taking pictures by 
light, on a silver plate or upon paper (37, 374, 1839; 38, 
97, 1840, etc.). Before many years passed, the Journal 
had occasion to show that these novel photographic 
delineations could be made useful in the investigation of 
problems in botany. In the pages of the Journal it would 
be easily possible to trace the development of this art in 


Goodale—Development of Botany Since 1818. 408 


its relations to natural history. Silliman possessed 
great sagacity in selecting for his enterprise all the nov- 
elties which promised to be of service in the advancement 
of science. In 1825 (9, 263) the Journal republished 
from the Edinburgh Journal of Science an essay by Dr. 
(afterwards Sir) William Jackson Hooker, on American 
Botany. In this essay the author states that ‘‘the 
various scientific Journals’’ which ‘‘are published in 
America, contain many memoirs upon the indigenous 
plants. Among the first of these in point of value, and 
we think also the first with regard to time, we must name 
Silliiman’s Journal of Science.’’ The author enumerates 
some of the contributors to the Journal and the titles of 
their papers. | 

It has been a useful practice of the Journal, almost 
from the first, to transfer to its pages memoirs which 
would otherwise be likely to escape the notice of the 
majority of American botanists. The book notices and 
the longer book reviews covered so wide a field that they 
placed the readers of the Journal in touch with nearly all 
of the current botanical literature both here and abroad. 
These critical notices did much towards the symmetrical 
development of botany in the United States. And as we 
shall now see, the Journal notices and reviews in the 
hands of Asa Gray continued to be one of the most 
important factors in the advancement of American 
botany. 


Asa GRAY AND THE JOURNAL. 


In 1834 there appears in the Journal (25, 346) a 
‘‘Sketch of the Mineralogy of a portion of Jefferson and 
St. Lawrence Counties, New York, by J. B. Crawe of 
Watertown and A. Gray of Utica, New York.’’ This 
appears to be the first mention in the Journal of the 
name of Dr. Asa Gray, who, shortly after that date, 
became thoroughly identified with its botanical interests. 
In the early part of his career both before and imme- 
diately- after graduating in medicine, Gray gave much 
attention to the different branches of natural history in 
its wide sense. He not only studied but taught ‘‘chemis- 
try, geology, mineralogy, and botany,’’ the latter branch 
being the one to which he devoted most of his attention. 
Among his early guides in the pursuit of botany may be 
mentioned Dr. Hadley, ‘‘who had learned some botany 


404  Goodale—Development of Botany Since 1818. 


from Dr. Ives of New Haven,’’ and Dr. Lewis C. Beck of 
Albany, author of Botany of the United States North of 
Virginia. At that period he made the acquaintance 
of Dr. John Torrey of New York, with whom he later 
became associated in most important descriptive work. 
During the years between his graduation in medicine and 
1842, the year when he came to Harvard College, his 
activities were diverse and intense; so that his prep- 
aration for his distinguished career was very broad and 
thorough. His first visit to Europe, in 1838, brought him 
into personal relations with a large number of the botan- 
ists of Great Britain and the Continent. This extensive 
acquaintance, added to his broad training, enabled him 
even from the outset to exert a profound influence upon 
the progress of his favorite science. He made the 
Journal tributary to this development. His name first 
appears as associate editor in 1853, but there are articles 
in the Journal from his pen which bear an earlier date. 
The first of these early botanical papers is the following: 
‘‘A Translation of a memoir entitled ‘Beitrage zur Lehre 
von der Befruchtung der Pflanzen,’ (contributions to the 
doctrine of the impregnation of plants, by A. J. C. 
Corda:) with prefatory remarks on the progress of dis- 
covery relative to vegetable fecundation; by Asa Gray, 
M. D.’’ (31, 308, 1887). Dr. Gray says that he made the 
translation from the German for his own private use, 
but thinking that it might be interesting to the Lyceum, 
he brought it before the Society, with ca cursory account 
of the progress of discovery respecting the fecundation 
of flowering plants, for the purpose of rendering the 
memoir more generally intelligible to those who are not 
particularly conversant with the present state of botan- 
ical science.’’ The translation occupies six pages of the 
Journal, while the prefatory remarks fill nine pages. 
The prefatory remarks constitute an exhaustive essay on 
the subject, embodied in attractive and perfectly clear 
language. The translator shows complete familiarity 
with the matter in hand and gives an adequate account of 
all the work done on the subject up to the date of 
M. Corda’s paper. A second important paper by him 
near this period is his review of ‘‘A Natural System of: 
Botany: or a systematic view of the Organization, Natu- 
ral Affinities, and Geographical Distribution of the whole 
Vegetable Kingdom ; ‘together with the use of the more 


Goodale—Development of Botany Since 1818. 405 


important species in Medicine, the Arts, and rural and 
domestic economy, by John Lindley. Second edition, 
with numerous additions and corrections, and a complete 
list of genera and their synonyms. London: 1836’’ (32, 
292, 1837). A very brief notice of this work in the first 
part of the volume for 1837 closes with the words, ‘‘A 
more extended notice of the work may be expected in the 
ensuing number of the Journal.’’ The extended notice 
proved to be a critical study of the work, signed by the 
initials A. G. which later became so familiar to readers 
of the Journal. Citation of a few of its sentences will 
indicate the strong and quiet manner in which Dr. Gray, 
even at the outset, wrote his notices of books. In speak- 
ing of the second edition of Professor Lindley’s work, 
he says: 


‘“Tt is not necessary to state that a treatise of this kind was 
greatly needed, or to allude to the peculiar qualifications of the 
learned and industrious author for the accomplishment of the 
task, or the high estimation in which the work is held in Europe. 
But we may properly offer our testimony respecting the great 
and favorable influence which it has exerted upon the progress 
of botanical science in the United States. Great as the merits 
of the work undoubtedly are, we must nevertheless be excused 
from adopting the terms of extravagant and sometimes equivocal 
eulogy employed by a popular author, who gravely informs his 
readers that no book, since printed Bibles were first sold in Paris 
by Dr. Faustus, ever excited so much surprise and wonder as 
did Dr. Torrey’s edition of Lindley’s Introduction to the Natural 
System of Botany. Now we can hardly believe that either the 
author or the American editor of the work referred to was ever 
in danger, as was honest Dr. Faustus, of being burned for witch- 
eraft, neither do we find anything in its pages calculated to 
produce such astonishing effects, except, perhaps, upon the 
minds of those botanists, if such they may be called, who had 
never dreamed of any important changes in the science since the 
appearance of good Dr. Turton’s translation of the Species 
Plantarum, and who speak of Jussieu as a writer who has greatly 
improved the natural orders of Linnzus.”’ 


In the Journal for 1840 there is a large group of 
unsigned book reviews under the heading, ‘‘ Brief notices 
of recent Botanical works, especially those most inter- 
esting to the student of North American Botany.’’ The 
first of these short reviews deals with the second section 
of Part VII of De Candolle’s Prodromus. In 1847 the 
consideration of the Prodromus is resumed by the same 


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a a he apm, sina Fs “ets c ati tm aeons are , es 4 ze les } } sie 
5 “ = = Ree a Fs = 5 Ss Sg ee eee st Sg ee SE aes —— 4 wt = ae = 

=~ << - - - or —— — —= ——— ——- se. a ae 


406 Goodale—Development of Botany Since 1818. 


author and the initials of A. G. are appended. This indi- 
cates that Dr. Gray was probably the writer of some of 
the unsigned book-reviews which had appeared in the Jour- 
nal between 1837 and 1840. Doubtless Siiliman availed 
himself of the assistance of his associates, Eli Ives 
and others, in New Haven, in the examination of current 
botanical literature, and it is extremely probable that he 
early secured help from young Dr. Gray, who had shown 
himself to be a keen critic as well as a pleasing writer. 
The notices of botanical works from 1840 bear marks of 
having been from the same hand. They cover an 
extremely wide range of subjects. While they are good- 
tempered they are critical, and they had much to do with 
the development of botany, in this country, along safe 
lines. ? 
Gray as Editor.—Gray’s name as associate editor of 
the Journal appears in 1853. He had been a welcome 
contributor, as we have seen, for many years. His 
influence upon the progress of botany in the United 
States was largely due to his connection with the Journal. 
His reviews extended over a very wide range, and supple- 
mented to a remarkable degree his other educational 
work. It must be permitted to allude here to his sagacity 
as a writer of educational treatises. In his first ele- 
mentary text-book, published in 1836, he expressed wholly 
original views in regard to certain phases of structure 
and function in plants, which became generally adopted 
at a later date. His Manual of Botany was constructed, 
and subsequent editions were kept, on a plan which made 
no appeal to those who wanted to work on lines of least 
resistance; in fact he had no patience with those who 
desired merely to ascertain the name of a plant. In the 
Journal he emphasizes the desirability of learning all the 
affinities of the plant under consideration. At a later 
period, when entirely new chapters had been opened in 
the life of plants, he sought by his contributions in the 
Journal to interest students in this wider outlook. 
Professor C. S. Sargent has selected with good judg- 
ment some of the more important scientific papers by 
Professor Gray and has re-published them in a con- 
venient form.!' Many of these papers were contributed 
to the Journal in the form of reviews. These reviews 


1 Scientific Papers of Asa Gray. Selected by Charles Sprague Sargent. 
Two volumes, Boston, 1889 (see notice in vol. 38, 419, 1889). _ 


Goodale—Development of Botany Since 1818. 407 


touch nearly every branch of the science of botany. As 
Sargent justly says, ‘‘ Many of the reviews are filled with 
original and suggestive observations, and taken together, 
furnish the best account of the development of 
botanical literature during the last fifty years that has 
vet been written.’’ In these longer reviews in the 
Journal, Gray was wont to take a book under review as 
affording an opportunity to illustrate some important 
subject, and many of the reviews are crowded with 
his expositions. For example, in his examination of 
vonMohl’s Vegetable Cell (15, 451, 1853) he takes up 
the whole subject of microscopic structure, so far as 
it was then understood, and he points out the probable 
errors of some of Mohl’s contemporaries, showing what 
and how great were Mohl’s own contributions to his- 
tology. Such a review isa landmark in the science. The 
physiology of the cell and the nutrition of the plant were 
favorite topics with Professor Gray, and he brought 
much of his knowledge in regard to them into such a 
review as that of Boussingault (25, 120, 1858) on the 
‘‘Infiuence of nitrates on the production of vegetable 
matter.’’ 

As a systematic botanist, Gray was naturally much 
interested in the vexed question of nomenclature of 
plants. One of his most important communications to 
the Journal is his review, in the volume for 1883 (26, 
417), of DeCandolle’s work on the subject. He deals 
with this strictly technical matter much as he did in a 
contribution to the Journal which he made in 1868 (46, 
63). In both of these papers he states with clearness the 
general features of the code of nomenclature. He says 
explicitly’ that the code does not make, but rather 
declares, the common law of botanists. The treatment 
of the subject at his hands would rightly impress a gen- 
eral reader as showing a strong desire to have common 
sense applied to doubtful cases, instead of insisting on 
inflexible rules. For this reason, his rule of practice was 
not always acceptable to those who were anxious to 
secure conformity to arbitrary rules at whatever cost. 
As he said in a paper published in the Journal in 1847 
(3, 302), ‘‘The difficulty of a reform increases with its 
necessity. It is much easier to state the evils than to 
relieve them; and the well-meant endeavors that have 
recently been made to this end, are, some of them, likely, 


408 Goodale—Development of Botany Since 1818. 


if adopted, to make confusion worse confounded.’’ This 
feeling led him to be very conservative in the matter of 
reform in nomenclature. 

This subject of botanical nomenclature illustrates a 
method frequently employed by Professor Gray to elu- 
cidate a difficult matter. He would find in the treatise 
under review a text, or texts, on which he would build a 
treatise of his own, and in this way he made clear his own 
views relative to most of the important phases of botany. 
When he faced controverted matters, his attitude still 
remained judicial. While he was tolerant of opinions 
which clashed with his own, he was always severe upon 
charlatanism and impatient of inaccuracy. The pages 
of the Journal contain many severe criticisms at his 
hands, but an unprejudiced person would say that the 
severity is merited. 

Sometimes, however, instead of reviewing a book or an 
address, he would follow the custom inaugurated early in 
the history of the Journal, of making copious extracts, 
and thus give to its readers an opportunity of examining 
materials which otherwise might not fall in their way. 

Gray’s contributions to the Journal comprise more 
than one thousand titles, without counting the memorial 
notices and the shorter obituary notes. In these notices 
he sums up in a few well-chosen words the contributions 
made to botany by his contemporaries. Even in the few 
instances in which he felt obliged to note with disap- 
proval some of the work, he expressed himself with per- 
sonal friendliness. The necrology, at it appeared from 
month to month, was a labor of love. All of the longer 
memorial notices are what it is the fashion now-a-days 
to call appreciations, and these are so happily phrased 
that it would seem as if the writer in many a case asked 
himself, ‘‘ Would my friend, about whom I am now writ- 
ing, make any change in this sketch?’’ | 

Gray on Darwimsm.——In October, 1859, Darwin’s 
epoch-making work, The Origin of Species, was pub- 
lished. An early copy was sent to the editor of the Jour- 
nal, Professor James D. Dana. This arrived in New 
Haven on December 21, but it was preceded by a personal 
letter which is of so much interest that it is here tran- 
scribed in full. It should be added that Dana was at this 
time in Europe where he was spending a year in the 
search for health after a serious nervous breakdown. 


Goodale—Development of Botany Since 1818. 409 


In his absence the book was noticed by Gray as stated 
below. The letter is, as follows: 


Down, Bromley, Kent. 
Nov. 11th, 1859. 
My dear Sir, 

I have sent you a copy of my Book (as yet only an abstract) on 
the Origin of Species. I know too well that the conclusion, at 
which I have arrived, will horrify you, but you will, I believe 
and hope, give me credit for at least an honest search after the 
truth. I hope that you will read my Book, straight through ; 
otherwise from the great condensation it will be unintelligible. 
Do not, I pray, think me so presumptuous as to hope to convert 
you; but if you can spare time to read it with care, and will then 
do what is far more important, keep the subject under my point 
of view for some little time occasionally before your mind, I have 
hopes that you will agree that more can be said in favour of the 
mutability of species, than is at first apparent. It took me many 
long years before I wholly gave up the common view of the sep- 
arate creation of each species. Believe me, with sincere respect 
and with cordial thanks for the many acts of scientific kindness 
which I have received from you, 

My dear Sir, 
Yours very sincerely, 
CHARLES DARWIN. 


In March, 1860 (29, 153), Gray published in the Journal 
an Bem orate and cautious review of Darwin’s work. He 
alluded to the absence of the chief editor of the Journal 
in the following words: 


““The duty of reviewing this volume in the American Journal 
of Science would naturally devolve upon the principal editor 
whose wide observation and profound knowledge of various 
departments of natural history, as well as of geology, particu- 
larly qualify him for the task. But he has been obliged to lay 
aside his pen to seek in distant lands the entire repose from 
scientific labor so essential to the restoration of his health, a 
consummation devoutly to be wished and confidently to be 
expected. Interested as Mr. Dana would be in this volume, he 
could not be expected to accept its doctrine. Views so idealistic 
as those upon which his ‘Thoughts upon Species’ are grounded, 
will not harmonize readily with a doctrine so thoroughly natur- 
alistic as that of Mr. Darwin . . . Between the doctrines of 
this volume and those of the great naturalist whose name adorns 
the title-page of this Journal [Mr. Agassiz] the widest diver- 
gence appears.’’ 


Gray then proceeds to contrast the two views of Dar- 


410 Goodale—Development of Botany Since 1818. 


win and Agassiz, ‘‘for this contrast brings out most 
prominently and sets in strongest light and shade the 
main features of the theory of the origination of species 
by means of Natural Selection.’’ He then states both 
sides with great fairness, and proceeds: 


‘“Who shall decide between such extreme views so ably main- 
tained on either hand, and say how much truth there may be 
ineach. The present reviewer has not the presumption to under- 
take such a task. Having no prepossession in favor of natur- 
alistic theories, but struck with the eminent ability of Mr. 
Darwin’s work, and charmed with its fairness, our humbler duty 
will be performed if, laying aside prejudice as much as we ean, 
we shall succeed in giving a fair account of its method and argu- 
ment, offering by the way a few suggestions such as might occur 
to any naturalist of an inquiring mind. An editorial character 
for this article must in justice be disclaimed. The plural pro- 
noun is employed not to give editorial weight, but to avoid even 
the appearance of egotism and also the circumlocution which 
attends a rigorous adherence to the impersonal style.’’ 


In this review he moves slowly and thoughtfully, but 
not timidly, over the new paths. There is no clear indi- 
cation in the review that he has yet made up his mind as 
to the validity of Darwin’s hypothesis. But; in a sec- 
ond article appearing in the Journal for September of 
the same year (30, 226), under the title ‘‘ Discussion 
between two readers of Darwin’s treatise on the origin 
of species upon its natural theology’’ Gray plainly begins 
to incline to take a very favorable view of the, Darwinian 
theory, and makes use of the following ingenious illus- 
tration to show that it is not inconsistent with theistic 
design. A few paragraphs here quoted show the felicity 
of his style in a controverted matter : 


‘‘Recall a woman of a past generation and show her a web 
of cloth; ask her how it was made, and she will say that the 
wool or cotton was carded, spun, and woven by hand. When 
you tell her it was not made by manual labor, that probably no 
hands have touched the materials throughout the process, it 1s 
possible that she might at first regard your statement as tanta- 
mount to the assertion that the cloth was made without design. 
If she did, she would not credit your statement. If you 
patiently explained to her the theory of carding-machines, spin- 
ning-jennies, and power-looms, would her reception of your 
explanation weaken her conviction that the cloth was the result 
of design? It is certain that she would believe in design as 
firmly as before, and that this belief would be attended by a 


Goodale—Development of Botany Since 1818. 411 


higher conception and reverent admiration of a wisdom, skill, 
and power greatly beyond anything she had previously conceived 
possible. ’’ 


By this review Gray disarmed hostility to such an 
extent that some persons who had been antagonistic to 
Darwinism accepted it with only slight reservation. 
It may be fairly claimed that the Journal bore a leading 
part in influencing the views of naturalists in America 
in regard to the Darwinian theory. 

Dr. Gray soon put the Darwinian hypothesis to a 
severe test. In the Journal for 1840 he had called atten- 
tion to the remarkable similarity which exists between 
the flora of Japan and a part of the temperate portion of 
North America. The first notice of this subject by him 
occurs in a short review of Dr. Zucearini’s ‘‘Flora 
Japonica,’’ a work based on material furnished by 
Dr. Siebold, who had long lived in Japan. In this 
review (39, 175, 1840), he enumerates certain plants com- 
mon to the two regions, and says, “‘It is interesting to 
remark how many of our characteristic genera are repro- 
duced. in Japan, not to speak of striking analogous 
forms.’’ Ina subsequent paper (28, 187, 1859), he recurs 
to this subject, and, after alluding to geological data fur- 
nished by J. D. Dana, he says: 


‘“T cannot resist the conclusion that the extant vegetable king- 
dom has a long and eventful history, and that the explanation 
of apparent anomalies in the geographical distribution of species 
may be found in the various and prolonged climatic or other 
vicissitudes to which they have been subject in earlier times; 
that the occurrence of certain species, formerly supposed to be 
peculiar to North America, in a remote or antipodal region, 
affords in itself no presumption that they were originated there, 
and that interchange of plants between eastern North America 
and eastern Asia is explicable upon the most natural and gener- 
ally received hypothesis (or at least offers no greater difficulty 
than does the arctic flora, the general homogeneousness of which 
round the world has always been thought compatible with local 
origin of the species) and is perhaps not more extensive than 
might be expected under the circumstances. That the inter- 
change has mainly taken place in high northern latitudes, and 
that the isothermal lines have in earlier times turned northward 
on our eastern and southward on our northwest coast, as they 
do now, are points which go far towards explaining why eastern 
North America, rather than Oregon and California, has been 
mainly coneerned in this mterchange, and why the temperate 


419 Goodale—Development of Botany Since 1818. 


interchange, even with Europe, has principally taken place 
through Asia.’’ 


This paper was communicated in 1859, on the eve of 
the publication of Darwin’s Origin of Species. Ata later 
date he applied the Darwinian theory to the possible solu- 
tion of the problem, and came to the conclusion that the 
two floras had a common origin in the Arctic zone, during 
the Tertiary period, or the Cretaceous which preceded it, 
and the descendants had made their way down different 
lines towards the south, the species varying under differ- 
ent climatic conditions, and thus exhibiting similarity but 
not absolute identity of form. Before the American 
Association for the Advancement of Science, in his Pres- 
idential address, in 1872, he used the following language: 


‘* According to these views, as regards plants at least, the 
adaptation to successive times and changed conditions has been 
maintained, not by absolute renewals, but by gradual modifica- 
tions. I, for one, cannot doubt that the present existing species 
are the lineal successors of those that garnished the earth in the 
old time before them, and that they were as well adapted to 
their surroundings then, as those which flourish and bloom around 
us are to their conditions now. Order and exquisite adaptation 
did not wait for man’s coming, nor were they ever stereotyped. 
Organic Nature—by which I mean the system and totality of 
living things, and their adaptation to each other and to the 
world—with all its apparent and indeed real stability, should 
be likened, not to the ocean, which varies only by tidal oscilla- 
tions from a fixed level to which it is always returning, but 
rather to a river, so vast that we can neither discern its shores 
nor reach its sources, whose onward flow-is not less actual 
because too slow to be observed by the ephemere which hover 
over its surface, or are borne upon its bosom.’’ 


Gray’s active interest in the Journal continued until 
the very end of his life. There were many critical 
notices from his pen in 1887. His last contribution to its 
pages was the botanical necrology, which appeared post- 
humously in volume 35, of the third series (1888). His 
connection with the J ournal cover ed, therefore, a pened 
of more than a half a century of its life2 

The changes that were wrought in botany by the 
application of Darwinism were far reaching. Attempts 
were promptly made to reconstruct the system of botan- 
ical classification on the basis of descent. The more suc- 


2 A notice of Gray’s life and works is given by his life-long friend, J. D. 
Dana, in the Journal in 1888 (35, 181-203). 


Goodale—Development of Botany Since 1818. +18 


cessful of these endeavors met with welcome, and now 
form the groundwork of arrangement of families, genera, 
and species, in the Herbaria in this country, in the man- 
uals of descriptive botany, and in the text-books of higher 
gerade. This overturn did not take place until after 
Gray’s death, although he foresaw that the revolution 
was impending. 

One of the most obvious changes was that which gave 
a high degree of prominence in American school treatises 
to the study of the lower instead of the higher or flower- 
ing plants, these latter being treated merely as members 
in a long series, and with scant consideration. But of 
late years, there has been a renewed popular interest in 
the phenogamia, leading to a more thorough investiga- 
tion of local floras, and also to the examination of the 
relations of plants to their surroundings. The results 
of a large part of this technical work are published in 
strictly botanical periodicals and now-a-days seldom find 
a place in the pages of a general journal of science. 


CRYPTOGAMIC BOTANY IN THE JOURNAL SINCE 1846. 


In glancing rapidly at the First Series it has been seen 
that a fair share of attention was early paid by the Jour- 
nal to the flowerless plants. So far as the means and 
methods of the time permitted, the ferns, mosses, lichens, 
and the larger alge and fungi of America were studied 
assiduously and important results were published, chiefly 
on the side of systematic botany. 

The Second Series comprises the years between 1846 
and 1871. In this series one finds that the range of 
eryptogamic botany is much widened. Besides inter- 
esting book notices relative to these plants, there are a‘ 
good many papers on the larger fungi, on the alge, and 
mosses. Here are contributions by Curtis, by Ravenel, 
by Bailey, and by Sullivant. The lichens are treated of 
in detail by Tuckerman, and there are some excellent 
translations by Dr. Engelmann of papers by Alexander 
Braun. Some of the destructive fungi are considered, as 
might well be the case in the period of the potato famine. 
It is in these years that one first finds the name of 
Daniel Cady Eaton, who later had so much to do with 
developing an interest in the subject of ferns in this 
country. He was a frequent contributor of critical 
notices. 


414 Goodale—Development of Botany Since 1818. 


Cryptogamic Botany, as it is now understood, is a 
comparatively modern branch of science. The appli- 
ances and the methods for investigating the more obscure 
groups, and especially for revealing the successive stages 
of their development, were unsatisfactory until the latter 
half of the last century. Gray recognized this condition 
of affairs, and appreciated the importance of the new 
methods and the better appliances. Therefore he viewed 
with satisfaction the pursuit of these studies abroad by 
one of his students and assistants, William G. Farlow. 
Dr. Farlow carried to his studies under DeBary and 
others unusual powers of observation and great indus- 
try. He speedily became an accomplished investigator in 
cryptogamic botany and enriched the science by notable 
discoveries, one of which to-day bears his name in botan- 
ical literature. On his return to the United States, 
Farlow entered at once upon a successful career as an 
inspiring teacher and a fruitful investigator. He 
became a frequent contributor to the Journal, keeping its 
readers in touch with the more important additions to 
cryptogamic botany. He had wisely chosen to deal with 
the whole field, and consequently he has been able to pre- 
serve a better perspective than is kept by the extreme 
specialist. The greater number of cryptogamic botanists 
in this country have been under Professor Farlow’s 
instruction. 


SYSTEMATIC AND GEOGRAPHICAL BoTANY OF LATE YEARS. 


The usefulness of the Journal in descriptive systematic 
botany of phanerogams is shown not only by its accept- 
ance of the leading features of DeCandolle’s Phytog- 

‘ raphy, where very exact methods are inculeated, but by 
the very numerous contributions by Sereno Watson and 
others at the Harvard University Herbarium, as well as 
from private systematists. It is in the pages of the 
Journal that one finds the record of much of the critical 
work of Tuckerman and of Engelmann, in interesting 
Phanerogamia. Of late years the Journal has had the 
privilege of publishing a good deal of the careful work of 
Theo Holm, in the difficult groups of Cyperacez, and also 
his admirable studies in the morphology and the anatomy 
of certain interesting plants of higher orders. 

Attention was called, in passing, to Gray’s deep inter- 
est in geographical botany. In this important branch, 


— ss ————————————— Se a = === Sp ae a ees es Ce = Se 


=, 


Goodale—Development of Botany Since 1818. 415 


besides his contributions, one finds, among many others, 
such papers as LeConte’s ‘‘Flora of the Coast Islands of 
California in Relation to Recent Changes of Physical 
Geography’’ (34, 457, 1887), and Sargent’s ‘‘Forests of 
Central Nevada’’ (17, 417, 1879). Examination reveals 
a surprising number of communications which bear indi- 
rectly upon this subject. 


PALEONTOLOGICAL BOTANY. 


When the Journal began its career, the subject of fossil 
plants was very obscure. Brongniart’s papers, espe- 
cially the Journal translations, enabled the students in 
America to undertake the investigation of such fossils 
and the results were to a considerable extent published 
in the Journal. Since the subject belongs as much to 
geology as to botany, it finds its appropriate home in the 
pages of the Journal. The recent papers on this topic 
show how great has been the advance in methods and 
results since the early days of the Journal’s century. 
Under the care of George R. Wieland, the communica- 
tions and the bibliographical notices of paleontological 
treatises show the progress which he and others are mak- 
ing in this attractive field. 


Economic Botany, PLANT PHYSIOLOGY, ETC. 


At the outset, the Journal, as we have seen, devoted 
much attention to certain phases of economic botany, and, 
even down to the present, it has maintained its hold upon 
the subject. The correspondence of Jerome Nicklés from 
1853 to 1867 brought before its readers a vast number of 
valuable items which would not in any other way have 
been known to them. And the Journal dealt wisely with 
the scientific side of agriculture, under the hands of S. W. 
Johnson and J. H. Gilbert, and others, placing it on its 
proper basis. This work was supplemented by Norton’s 
remarkable work in the chemistry of certain plants, the 
oat, for example, and certain plant-products. In fact it 
might ~-be possible to construct from the pages of the 
Journal a fair synopsis of the important principles of 
agronomy. 

Physiology has been represented not only by the 
studies which had been inaugurated and stimulated by the 
Darwinian theory, such as the cross-fertilization and 


5 NG Ee 


=D pe 


416 Goodale—Development of Botany Since 1818. 


the close-fertilization of plants, plant-movements, and 
the like, but there have been a good many special com- 
munications, such as Dandeno on toxicity, Plowman on 
electrical relations, and ionization, and W. P. Wilson on 
respiration. 

There are many broad philosophical questions which 
have found an appropriate home in the Journal, such as 
‘“The Plant-individual in its relation to the species’’ 
(Alexander Braun, 19, 297, 1855; 20)) 18iaoae 
and ‘‘The analogy between the mode of reproduc- 
tion in plants and the alternation of generations 
observed in some radiata’’ (J.D. Dana, 10, 341, 1850). 
Akin to these are many of the reflections which one 
finds scattered throughout the pages of the Journal, 
frequently in minor book-notices. As might be expected, 
some attention has been paid to the very special branch of 
botany which is strictly called medical. For example, 
early in its history, the Journal published a long treatise 
by Dr. William Tully (2, 45, 1820), on the ergot of rye. 
This is considered from a structural as well as from a 
medical point of view and is decidedly ahead of the time 
in which it was written. There are a few references to 
vegetable poisons, and there is a fascinating account of 
the effect of the common white ash on the activities of 
the rattlesnake. In short it may be said that the editor 
did much towards making the Journal readable as well 
as strictly scientific. 

The list of reviewers who have been permitted to use 
the pages of the Journal for notices of botanical and 
allied books in recent years is pretty long. One finds the 
initials of Wesley R. Coe, George P. Clinton, Arthur L. 
Dean, Alexander W. Evans, William G. Farlow, George 
L. Goodale, Arthur H. Graves, Herbert EK. Gregory, 
Lafayette B. Mendel, Leo. F. Rettger, Benjamin L. Robin- 
son, George R. Wieland, and others. 

At the present time, in the biological sciences, as in 
every department of thought, there is great specialization, 
and each specialty demands its own private organ of 
publication. Naturally this has led to a falling off in the 
botanical communications to the Journal, but it cannot be 
forgotten that the history of North American Botany has 
been largely recorded in its pages. 


% zi <=) : < 
: \ = | 


“AUG 14 1916 
te g PATENT oe - 


“ey 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


om 


Arr. XIII.—The Melting Points of Cristobalite and 
Tridymite; by J. B. Ferauson and H. E. Merwin. 


I. Cristobalite. 


While investigating the system CaO-MgO-Si0, at 
high temperatures, we were impressed with the need for 
further work on the melting point of cristobalite, the high 
temperature form of silica, and wish in this paper to 
present some new results. 

In 1906 Day and Shepherd! upon heating finely pow- 
dered quartz in an iridium furnace at different tempera- 
tures observed a partial melting even at 1650°, and noting 
the sluggish nature of this phenomenon estimated the 
melting point of silica to be at 1625°.2, The experimental 
conditions were such, however, that it is uncertain to 
which crystalline form of silica this melting point 
belongs.® 

In 1912 Endell and Rieke* determined the melting 
point of cristobalite to be 1685° +10°. They heated 
eristobalite powder in an iridium furnace and measured 
their temperatures by means of an Ir:Ir-Ru thermoele- 
ment. They carefully calibrated this thermoelement at 
the gold, palladium and platinum points, but such an 
element under their working conditions could not remain 
unchanged even during one experiment. The amount of 
the resulting contamination and the direction of its ther- 


+A. L. Day and E. S. Shepherd, this Journal, 22, 265, 1906. 
2 Recaleulated on the basis of the temperature ‘seale given by R. B. Sosman, 
ibid., 30, 1-15, 1910. 
20. N. Fenner, ibid., 36, 381, 1913. 
“K. Endell and R. Rieke, Z. anorg. Chem., 79, 239, 1913. 


Am. Jour. Sct.—FourtH Srrigs, Vout. XLVI, No. 272.—Aveust, 1918. 
14 


418 Ferguson and Merwin—Melting Points of 


moelectric effect is somewhat doubtful, but probably 
would lead to too low results. 
The following year Fenner’ attempted to confirm these 
results of Emdell and Rieke and heated cristobalite in a 
eraphite furnace which had been specially designed to 
prevent changes in either his charges or the Pt:Pt-Rh 


Itwee a. 


Orr 
. . 
wees 


ehatee, 
+e? 
avee hs 
pe A 
erie 
Stet 
of 
ode 
SORA 
2 

oe one 
E 


o- 
- 
ee 
° 
. 
te 


Be: | ZZ 2 
Magnesia Hard burned Fire clay. Alundum. 
powder. magnesia. 


thermoelement by the reducing gases. The first deter- 
minations indicated a melting temperature of 1680°-1690° 
thus confirming Endell and Rieke, but later he found that 
by prolonging the time of heating to half-an-hour, traces 
of fusion could be detected at much lower temperatures 
and so was led to place the real melting point at 1625°. 
Some doubt, however, was cast upon this value by 
Bowen,° although he made no direct determination of the 


> C. N. Fenner, loc. cit. 
SN. L. Bowen, this Journal, 38, 218, 1914. 


Cristobalite and Tridymite. 419 


melting point. In the ternary system diopside-fosterite- 
silica he found the eristobalite liquidus rose too steeply 
from the boundary curve separating the silica field from 
the pyroxene field to warrant such a low value, and sug- 
gested that the melting point probably was at a higher 


Kig..2. 


Section A-A, 


MB ard burned magnesia. 


A\ é 
Section B-B. ERCOrne 


Marquardt porcelain, 


temperature even than that assigned to it by Endell and 
Rieke. 

Our work on the system CaO-MgO-Si0, has confirmed 
Bowen’s results and has led to our undertaking the rede- 
termination of the melting point of cristobalite. 

Such an investigation required a furnace capable of 
maintaining a charge at temperatures above 1700° for 
periods of time up to an hour in length. The iridium- 
tube furnace will reach these temperatures but ‘is 


420 Ferguson and Merwin—Melting Points of 


unsuitable for such long heats; the ordinary platinum 
furnace is not suitable, therefore one of different design 
built on the well-known cascade principle was evolved and 
did duty throughout the entire investigation. 

A vertical cross-section of this furnace is shown in 
fig. 1. The outer heater, of platinum wire 0-8 mm. in 
diameter, is wound on a helically grooved alundum tube 
and held in place with alundum cement; the outer insula- 
tion consists of magnesia powder surrounded by a heavy 
fire clay shell. The inner heater, of Pt-20% Rh wire 
0-5 mm. in diameter, is wound on a helically grooved 
magnesia tube and held in place by tie-wires of the same 
alloy. The two heaters are insulated from each other 
with magnesia powder and the furnace is so constructed 
as to facilitate the addition of more magnesia powder at 
any time.’ 

The quenching apparatus? with the Pt:Pt-10% Rh 
thermoelement and its leakage wire is shown in fig 2. 
The upper cap is cemented to the Marquardt porcelain 
tube but all the other parts are snug fitting and held in 
place by the wires. 

The operation of the furnace was very simple... Knough 
current was sent through the outer coil to maintain a 
temperature of 1450° in the furnace without the use of 
the inner coil. The furnace was then heated to the 
required higher temperature by passing the necessary 
current through the inner coil. The temperatures were 
measured by means of the usual potentiometer set-up, 
single shielding being used, and there was no trouble 
from electrical leakage. 

The determinations were made in the following man- 
ner: a small amount of the sample was wrapped up in 
platinum foil and tied with a platinum wire to the ther- 
moelement in such a way that it hung close to the 
thermoelement junction. The thermoelement tube with 
the charge was then inserted into the furnace which had 


7JIn the earlier runs several such additions were necessary during an 
afternoon. The magnesia did not pack evenly and between runs the caked 
material was broken up by means of a special iron drill. This assured a 
fairly uniform insulating layer and had it not been done there would have 
been spaces in which there was no insulating material except air between 
the heaters. 

® The usual form of quenching apparatus could not be used as experimenta- 
tion showed that the furnace was too small and the platinum too soft. The 
charge stuck to the globules of platinum which lined the furnace tube and 
which resulted from the fusing of the fine wire holding the charge. 


Cristobalite and Tridymite. 421 


previously been heated to approximately the desired tem- 
perature. After the heat treatment, the tube was quickly 
withdrawn and the charge plunged into mercury. When 
eold the charge was removed from the thermoelement, 
opened, and the sample examined microscopically. In 
some experiments two charges instead of one were tied to 
the thermoelement, but on account of the small diameter 
of the furnace tube more could not be used at one time. 


Results. 


1. CaO-MgO-SiO, charges made up in the usual manner by 
repeated grindings and heatings to about 1600°. Crystals of 
eristobalite form during the heatings and are present in the 
charge used for quenchings. 


(a) CaO 24, MeO 7, SiO, 69. 


Temperature Sample Quenched 
(corrected). after : Results. 


a601° 30 min. Almost entirely glass but a few 
erains of eristobalite which 
appear to be dissolving in the 


glass. 
ib 120 min. Glass. 
Part of this latter quench 
heated again. 
1638° 30 min. A number of good erystals of 
eristobalite. _ 
A second part of this latter 
quench taken and brought to 
the required temperature in 6 
minutes. 
1638° 20 min. A number of good crystals. 


(b) CaO 11-5, MgO 3-5, SiO, 85. 


Temperature Sample Quenched 


(corrected). after : Results. 
GliGia: = a 30 min. Glass. 
1708° 30 min. A quantity of large cristobalite 


erystals and some glass. 


2. Silica glass tube heated for 1% hour at 1550° by R. B. Sos- 
man. Material: cristobalite with specks of more highly refract- 
ing glass. | 


422 Ferguson and Merwin—Melting Points of 


Temperature Sample Quenched 
(corrected ). abel: pee Results. 

1653 7 30 min. A little more glass, some having 
higher refraction and some lower 
than cristobalite. 

OAS 30 min. 2-3% glass all having lower re- 
fraction than cristobalite. 


3. Single clear crystal of quartz. 
Temperature Sample Quenched 
(corrected ) . after : Results. 

T69te 60 min. Quartz with layer of glass, and 
then outside a homogeneous - 
layer of cristobalite. 

4. Clear quartz crystals that had been heated all night at 
1550°. Material was entirely crystallized to cristobalite. 
Temperature Sample Quenched 


(corrected). after : Results. 

1698° 30 min. No glass, the crystals perhaps a 
little larger. 

oe 30 min. All glass. 

ITS 30 min. Trace of crystals, and rest glass. 

1708° 32 min. Main part of charge all crystals, 
but a few grains were mostly 
olass. 


5. Silica glass made by heating some of the cristobalite 
obtained from clear quartz as in (3) to 17387°. 
Temperature Sample Quenched 
(corrected). after: Results. 
1646° 45 min. Not all erystallized, but where 
erystallized at all the whole mass 
is eristobalite. 
1679= 30 min. All erystals, not a trace of glass. 


6. Baker and Adamson specially purified quartz finely ground ; 
contains many minute inclusions which are not determinable but 
are mostly of much lower refractive index; after heating for two 
hours at 1550° has all changed to ecristobalite with the exception 
of some minute specks too small to identify. 


Temperature Sample Quenched 


(corrected ). after : Results. 
1646° 45 min. Unchanged. 
WOT 30 min. Trace of material with refrac- 


tion higher than _ eristobalite; 
probably glass. 

1693° 38 min. Charge seems similar to that 
ait Oo ? 


Cristobalite and Tridymite. 423 


1705°.- 30 min. 34, Glass. 
1714° > 30 min. Trace of erystals + glass. 
1714° 10 min. Trace of crystals + glass. 


- 


i. Cristobalite made by heating clear quartz crystals for 144 
hours at temperatures ranging from 1300 to 1400°. Two lots 
were made at the same time, one from lumps a few mm. in diam- 
eter, the other from powder 0-5 mm. and finer. At the end of 
100 hours there was present a few percent of unconverted quartz 
in each lot, and at the end of 144 hours traces of quartz. Also 
during the final selection of material free from quartz, some 
of the larger grains were found to have hard, clear nuclei of 
tridymite. The ecristobalite was very white and friable. 


Temperature Sample Quenched 


(corrected). after : Results. 
1695° 22 min. No melting detected. 
LOT, 15 min. A few grains showed traces of 


melting; others were melted 
into clear beads. 

aba 18 min. All melted to one mass of clear 
glass. 


- After heating No. 4, a calibration at the Pd point gave 
16040 microvolts, after No. 6, 16025 microvolts, and after 
No. 7, 16080 microvolts. The high value after No. 7 was 
the result of the cutting out of the most contaminated 
portions of the thermoelement prior to the No. 7 experi- 
ments. A standard element gives 16140 microvolts. 


Discussion of Results on Cristobalite. 


The fluxing of cristobalite crystals above the liquidus by 
a ternary melt very high in silica appears to be slow com- 
pared with the growth of cristobalite crystals in a simi- 
lar melt the same number of degrees below the liquidus. 
A possible explanation of the phenomenon may be that 
during fluxing the crystal is surrounded by a thin film of 
ereater silica content and during crystallization a thin 
film of less silica content than the average composition of 
the melt. ‘Fhe rate mentioned would be a function of the 
viscosity of this liquid film. 

The silica-glass tube (No. 2 above), although supposed 
to be very pure material, carried enough impurity to give 
a large temperature interval of melting. The highly re- 
fracting specks were evidence of impurity, and possibly a 
similar explanation may account for Fenner’s results. 


424 Ferguson and Merwin—Melting Points of 


The superheating of quartz is perhaps better illus- 
trated by experiment 3 than by any experiment that has 
heretofore been made. Im the case of pure substances 
this phenomenon is probably due to the rigidity of the 
crystals themselves and, unlike the solution of a crystal 
in a melt of different composition, is independent of the 
viscosity of the melt. 

Cristobalite formed at a temperature of 1350° behaved 
in a similar manner to that formed at higher tempera- 
tures. If Fenner’s® conception of the molecular struc- 
ture of cristobalite is correct, the molecular readjustment 
must take place in the crystals themselves. 

The melting point!® of ceristobalite is Hie a at 
1710° + 10°. This is as narrow a limit as the observa- 
tions will permit, although the temperature measure- 
ments were more accurate. (See results on tridymite.) 


IT. Tridymite. 


In an attempt to duplicate the observations of Le Cha- 
telier!! upon the tridymite-cristobalite inversion we were 
fortunately able to obtain and examine microscopically 
specimens of silica bricks from two types of glass fur- 
naces which had been in continuous operation for a long 
time. The one specimen from the crown of a furnace of 
the regenerative type in which the direction of the fiue 
gases is reversed every 15 or 20 minutes contained good 
erystals of tridymite while the other specimen from the 
crown of a furnace of the recuperative type contained 
cristobalite. There could be no question but that this 
latter specimen was subjected to a higher temperature 
than the former since the flames continuously played 
upon it and it was not affected by the cold air which 
leaked into the furnace through the crevices about the 
furnace door. 

These observations do not agree with those made by 
Le Chatelier, and we therefore ‘decided to determine the 
melting point of tridymite which if obtained would 
clearly indicate the relation this form of silica bears to 
cristobalite. 


°N. L. Bowen, this Journal, 38, 218, 1914; C. N. Fenner, ibid., 36, 366, 
HONS: 

The softening points of silica bricks were found by C. W. Kanolt to be 
1700, 1705, 1700 respectively. Technologic paper No. 10, Bur. Standards 
1912. 

11 Henry Le Chatelier, Bull. Soc. Fr. Min. 1917, p. 44. 


Cristobalite and. Tridymite. 425 


The furnace and set-up used in the determination of 
the melting point of cristobalite were available and were 
used without change in this work. 


Results. 

1. Natural tridymite, kindly furnished by G. P. Merrill from 
the collection in the New National Museum. Occurrence: Lan- 
der Co., Nevada, associated with ‘‘wood tin,’’ described by 
A. Knopf ;? aggregate having radiating structure and no vis- 
ible impurities except minute amounts of granular quartz; 
refractive index measured 0-003 higher than the other four sam- 
ples here described. 


Temperature Sample Quenched 


(corrected). after : Results. 
1G55° 4 min. The quartz alone had fused. 
1659° 10 min. 66 a4 (4 (74 é¢ 
(1659-82° ) 5 min. Practically all melted. 
1667° 10 min. Quartz only melted. 
1675° 10 min. Practically all melted. 
fafa" 20 min. A few grains partly melted, but 


| many entirely melted. 

2. Artificial tridymite. After heating some pure quartz 
crystals at approximately 1350° for 144 hours the quartz has 
inverted mostly to cristobalite but a few grains inverted to tridy- 
mite and these grains were used in these experiments. (See 
results under No. 7 above.) 


Temperature Sample Quenched 


(corrected). after: Results. 
1667° 10 min. The tridymite in both cases in- 
1677° 6 min. verted to dense grains of cristo- 


balite without melting. 


3. Natural tridymite. Locality: Cerro San Cristobal, near 
Pachuca, Mexico. National Museum No. 51,288. Clear, faceted 
erystals, having the same refractive index as (1) the artificial 
tridymite above, (2) the tridymite from the glass furnace, 
(3) some natural tridymite crystals obtained through the kind- 
ness of Mr. E. S. Larsen, Jr., of the U. S. Geological Survey. 


Sample Quenched 
Temperature after: Results. 
1677° 5) min. Many grains all glass, some few 
partly melted. ! 
1667° 10 min. A clear erystal which showed no 


sign of inversion or melting. 


2 U. S. Geol. Survey, Bull. 640, 133, 1916. Schaller’s values of the 
refractive indices of this material are about 0-004 higher than Fenner’s for 
pure tridymite. 


496 Cristobalite and Tridymite. 


The thermoelements when calibrated at the Pd point 
gave 16080 microvolts. A standard element gives 16140 
microvolts. 


Discussion of Results on Tridymite and Cristobalite. 


This is, we believe, the first time that the inversion of 
quartz to tridymite by dry heat has ever been observed 
experimentally. In No. 2 we have inverted quartz to 
tridymite and then this tridymite to cristobalite by means 
of this agency alone. 'Tridymite melts sharply at a tem- 
perature: or 16707 22 102. 

Our results confirm the earlier observations of Fen- 
ner,’*? who considered the region of stability of cristo- 
balite to be above that of tridymite. 


Summary. 


1. A new type of furnace has been described capable 
of maintaining, in an oxidizing atmosphere, a charge at 
temperatures slightly above 1700° for periods of time of 
at least a few hours. ‘This furnace is constructed on the 
cascade principle; the inner coil is of an alloy of plat- 
inum with 20% rhodium, the outer coil of pure platinum. 
The two coils are insulated from each other by well 
burned magnesia powder and the inner coil is wound on a 
helically grooved magnesia tube. 

2. The melting point of cristobalite has been redeter- 
mined with the aid of the above-described furnace. ‘The 
new value 1s A102 ==102C: 

3. The melting point of tridymite has been determined 
ror the nrst mime It melts at L670? == eC: 

4. Quartz has been directly inverted to tridymite by 
means of dry heat alone. 

The region of stability for cristobalite lies above that 
for tridymite. 

Geophysical Laboratory, 


Carnegie Institution of Washington, 
Washington, D. C. 


18 C, N. Fenner, this Journal, 36, 381, 1913. 


Gooch & Scott—Determination of Vanadic Acid. 427 


Art. XIV.—The Application of Rapidly Rotating Metal- 
lic Reductors wm the Determination of Vanadic Acid; 
by F. A. GoocH and WaurTer Scort. 


(Contributions from the Kent Chemical Laboratory of Yale Univ.,—ccci.) 
ie 
THE REDUCTION OF VANADIC ACID IN ANALYSIS. 


It has been shown by Edgar! that vanadic acid in solu- 
tion with sulphuric acid or hydrochloric acid may be 
reduced definitely to the condition of the tetroxide by the 
action of metallic silver, also that the reaction between 
silver and vanadie acid in presence of sulphuric acid, may 
be applied in extremely accurate methods for the deter- 
mination of vanadium, the amount of that element being 
indicated either by the loss in weight of the silver, by 
titration of the dissolved silver sulphate with standard 
thiocyanate, or by oxidation of the vanadium tetroxide 
by standard permanganate. It was found that massive 
silver in the form of fine wire (1:5 grm.) gave complete 
reduction of 0-1200 grm. V,O,, but only after long boiling 
(1 hr.) of the solution in contact with that metal, and 
that the form of silver best adapted to the purpose was 
electrolytic silver deposited from the nitrate solution as a 
‘‘bush’’ of finely divided crystals subsequently purified 
by boiling in dilute sulphuric acid, filtering off in an 
alundum crucible, and igniting to a low red heat. With 
silver thus prepared the action is very rapid in a boiling 
solution of the vanadie and sulphuric acids and a com- 
plete reduction of an amount of vanadic acid equivalent 
to 0-:1200 grm. of the pentoxide was obtained by boiling 
for ten minutes with 2 grm. of the silver. 

The work of which an account is here given originated 
in an attempt to substitute massive silver for the 
finely divided silver, the preparation of which is some- 
what elaborate. Subsequently the experimentation was 
extended to the similar use of copper and of zine as the 
reducing metal. In all the experiments to be described 
the vanadic acid acted upon by the reducer was hberated 
by sulphuric acid from a preparation of ammonium vana- 
date which yielded on ignition an average content of 
77-25% of vanadium pentoxide. 

1 Jour. Am. Chem. Soc., 38, 1297, 1916. 


== 


428 Gooch € Scott—Determination of Vanadic Acid. 


Reduction by Masswe Silver.—The first experiments 
with massive silver were made to test the effect of 
increasing the superficial area of the silver which is 
exposed to the action of the vanadic and sulphuric acids. 
In these experiments pure sheet silver weighing about 5 
germ. and measuring about 2 centimeters square and a 
millimeter thick was cut with radial slits, bent to rose 
form and placed in a trapped Erlenmeyer flask, in a solu- 
tion made by dissolving the ammonium vanadate in water 
(50 cm.*) and adding sulphuric acid. The solution was 
boiled, the volume of the liquid, 75 em.* at the start, being 
kept above 60 em.* by addition of water as necessary dur- 
ing the process. At the end of the boiling the silver was 
removed from the liquid, washed, dried by heating gently 
and weighed, the loss in weight representing the vana- 
dium pentoxide reduced according to the expression 
2Age V.O;. In three of these experiments, the reduced 
vanadie acid in hot solution was titrated by nearly N/10 
potassium permanganate standardized against sodium 
oxalate. A correction (amounting to 0-12 em.*?; 0-00082 
erm. in terms of V,O,;) for the permanganate required to 
produce a reading color in a similar solution of sul- 
phuric acid, silver sulphate and unreduced vanadie acid 
was applied in these determinations. The details of 
these experiments are given in Table I. 


TABLE I. 


Reduction of Vanadic Acid by Massie Silver in the 
Bowling Solution. 


taken as equivalent equivalent Error 
ammonium Lossof tolossof toKMnO, by lossof By KMnO, 

vanadate silver silver (corrected): silver process Time 
erm. erm. erm. erm. erm. erm. min. 

00776 . 0:0902  0:-0762 —0-0014 20 

00807 0:0950 0-0803 —0-0004 29 

0:0803 0:0941 0:0795 —0-0008 29 

0711 = 0:0920"..70:0777 0-0000 39 


6:0807  0:0950  0-6808° 0:0806..-—0-0004 =) omen 20 
0-0777  0-0920 0-0777  0-0778 0:0000 -+0:0001 30 
0:0803 0:0941 00795 0-0803 —0-0008 0-:0000 30 


These experiments show that massive silver of suffi- 
cient surface may effect the reduction of vanadie acid 
within a reasonable time from the boiling solutien con- 


Gooch & Scott—Determination of Vanadic Acid. 429 


taining sulphuric acid, a reacting surface of about 10 em.? 
of silver insuring the complete reduction of vanadie acid 
equivalent to about 0-08 grm. of vanadium pentoxide 
within thirty minutes. No advantage was gained when 
the liquid was stirred by a cylinder of silver or a silver- 
platinum couple rotating rapidly in the hot solution. 
We have, however, been able to effect a very considerable 
improvement in the rapidity of reduction of vanadic acid 
in presence of sulphuric acid by the use of a rapidly 
rotating anode of silver in the electrolytic cell containing 
the dissolved acids. 

Reduction with the Aid of the Silver Anode—lIt has 
been shown by Truchot? that when vanadic acid in the 
presence of very small amounts of sulphuric acid is sub- 
mitted to the slow action of an electric current of low 
amperage, between platinum electrodes, vanadium in a 
condition of oxidation lower than that of the tetroxide 
may be deposited upon the cathode. The presence of too 
much sulphuric acid interferes with this deposition. 
In some experimenting with the rapid reduction of 
vanadic acid between platinum electrodes in. dilute sul- 
phuriec acid and at high amperage we have found, as is 
natural (inasmuch as the reduced vanadium compounds 
remain in solution), that the reduction is irregular and 
dependent upon the relation of the areas of the anode and 
the cathode. Our attention was directed, therefore, to the 
use of an electrolytic cell in which a rapidly rotating 
cylinder of silver served as the anode. 

In the following experiments, the amounts of ammo- 
nium vanadate indicated (approximately 0-1 grm.) were 
dissolved in 75 em.® of hot water, sulphuric acid (10 em.’ 
1:1) was added and the solution was heated to the boiling 
temperature and then submitted to the action of the elec- 
tric current passing between a rotating silver anode and 
a stationary platinum cathode measuring 2 em. * 5 em. 
For the silver anode we made use of a cylindrical silver 
erucible, 10 em. long and 2-5 em. in diameter, dipping in the 
liquid to a depth of about 4 em. and exposing to action a 
surface of about 30 em.? which, after considerable use had 
resulted in the eating away of the bottom of the crucible 
so that the anode became an open tube, was practically 
doubled. The anode was attached to the rotating spindle 

? Ann. Chem. Anal. 7, 165, 1902. 


430 Gooch 


anadic Acid. 


by means of a bored rubber stopper and electrical con- 
nection was made between the iron spindle and the tubular 
anode by a strip of platinum foil held in contact with both 
by the pressure of the rubber stopper. 

The current was delivered from a 16-volt storage bat- 
tery and the rotating motor, on a 110-volt cirenit, was run 
at a rate of 700-900 revoluti tions per minute. In the action 
of this cell the vanadic acid was quickly reduced to the 
condition of the tetroxide and the reduction may pro- 
ceed further, but the action of the silver sulphate formed 
by the solution of the anode will automatically restore 
the condition of oxidation to that of the tetroxide with 
the precipitation of metallic silver, as shown by Gooch 
and Gilbert. The end of reduction to the stage of the 
tetroxide is therefore indicated by the appearance of pre- 
cipitated silver in suspension. After the electrolytic 
reduction the liquid was therefore boiled for five minutes 
to coagulate the suspended silver, filtered, diluted to a 
volume of 250 cm.*, again heated to boiling and titrated 
with standard potassium permanganate. The results 
of preliminary experiments showing the rate of reduc- 
tion under the conditions are given in A of Table II. 
The results of a final series of experiments in which 
the reduction was stopped when a distinct cloudiness 
appeared in the solution are given in B of Table Il. The 
experimentally determined correction for the amount of 
permanganate needed to produce color in the blank deter- 
mination (0-12 em.?) was precisely the same as in the 
experiments of Table I. It is plain that this procedure 
yields exact and regular results with great rapidity. 

Reduction with the Aid of the Copper Anode.—The 
successful use of the silver anode in the reduction of 
vanadie acid suggested the similar use of the cheaper 
copper. In the experiments immediately following the 
procedure was essentially similar to that adopted in the 
preceding experiments with the silver anode. 

In preliminary tests to determine the rate of reduction 
the anode was a hollow cylinder of commercial copper 
exposing a surface of about 25 em.? to the action of 60 cm.? 
of solution containing 5 cm.* of concentrated sulphuric 
acid. The platinum cathode measured 2 cm. by 9 cm. 
The results of these tests are given in Table IIL. 


* This Journal, 15, 389, 1903. 


Gooch & Scott—Determination of Vanadic Acid. 431 


TasBue If. 


Reduction of Vanadic Acid with the Aid of the Silver Anode in 
the Electrolytic Cell. 


V205 V0; Revolutions 
taken as found by Period of anode: Strength 
ammonium KMnO, of approximate of 
vanadate (corrected) Error reduction number per current 
grm., erm, erm. min. minute amp. 
A. 
0-0780 0211 — 0569 1 700-900 2 
0-0786 0639 —:0147 2 700-900 2 
0-0790 ‘0750 — 0040 3 700-900 2 
0-0783 ‘O741 — 0042 3 700-900 2 
0-0780 ‘0757 — 0023 4 700-900 2 
0-0781 0768 — 0013 + 700-900 2 
0:0779 ‘O774 — 0005 i) 700-900 2 
0-0779 0783 + -0004 dD 709-900 2 
0-0781 ‘O781 0000 6 700-900 2 
0-0785 O781 — 0004 6 700-900 2 
iB. 
0:0773 ‘O770 — 0005 aye 700-900 2 
0-0781 ‘0776 —:0605 a” 700-900 2 
0-0784 ‘0785 + :-0001 a” 700-900 2 
0-0786 0783 — (0005 a 700-900 2 
0-0781 ‘O781 ‘0000 ao 700-900 2 
0-0785 0787 +-0002 aye 700-900 2 
0-0778 0778 0000 oe 700-900 2 
0-0786 ‘0786 ‘0000 Sy 700-900 2 
0:0773 ‘OT74 +-0001 De 700-900 2 
0-0786 SOS — 0005 a” 700-900 2 
0-0776 Os +-0001 o* 700-900 2. 
0-0773 ‘0770 — 0003 ag 700-900 2 


*Approximate: to appearance of distinct cloudiness. 


These results were sufficient to show that the reduction 
proceeds more rapidly at the higher temperature and to 
serve as a guide in the following experiments in which 
over-reduction of vanadic acid was corrected by the addi- 
tion of silver sulphate, as in the procedure of Gooch and 
Gilbert,t boiling of the solution, and filtration from the 
precipitated silver. The correction to be apphed in the 
permanganate titration (determined by experiments in 
blank) proved to be somewhat variable when the anode 
was made of commercial copper; while with electrolytic 

= ioc. cit. 


432 Gooch & Scott—Determination of Vanadic Acid. 


copper the amount of the permanganate solution neces- 
sary to produce the reading color (in a solution which 
had undergone treatment precisely as in the usual deter- 
minations, excepting that the ammonium vanadate was 
added just before the titration and after the electrolysis, 
treatment with silver sulphate, boiling, and filtration) 
was regular and definite. 


TABLE: Lik: 


Rate of Reduction of Vanadic Acid with the Aid of . 
the Anode of Commercial Copper: 


Prelominary Experments. 


V205 V.0s Revolutions 
taken as found by Period of Strength 
ammonium KMn0O, of anode of 
vanadate (corrected) Error reduction (approx.) current 
erm. erm. erm. min. per min. amp. 
A. 


At room temperature: 20°-23°. 


0-0781 0:0203 —0-0578 2 800 2 
0-0784 0:0292 —0-0492 3 800 2 
0-0779 0:0432 —0-0347 4 800 2 
0-0784 0-0533 —0-0251 5 800 2 
0-0780 0:0587 —0-0193 6 900 2 
0-0781 0:0680 —0-0101 7 800 2 
0-0783 00787 +0-0004 g 800 2 
0-0784 0:0953 -+0-0169 at 800 2 
B. 

| Started at boiling temperature. 

0-0779 0-0563 —0-0216 2 800 2 
0-0784 0:0809 -+0-0025 3 800 2 
0-0779 0:0944  -+0-0165 4 800 2 


In the experiments recorded in Table IV, therefore, 
the anode was made of electrolytic copper plated from a 
solution of iron-free copper sulphate upon a silver tube. 
The conditions of action were similar to those of the pre- 
viously described experiments with the silver anode: 
viz.—volume of solution heated to boiling at the outset, 75 
em.*?; sulphuric acid (cone.), 5 em.*; diameter of anode 
2-5 em. and area exposed to action, 30 em.?; area of plat- 
inum cathode, 10 em.?; revolutions of anode, about 800 
per minute. At the end of the process of reduction the 


Gooch & Scott—Determination of Vanadic Acid. 433 


solution was treated with silver sulphate (10 cem.* of the 
saturated solution), heated to boiling, filtered from 
the precipitated silver, diluted to a volume of 150 em.? 
and titrated with standard permanganate. The carefully 
determined correction in blank, amounting very regularly 
to 0-2 em.® of the permanganate solution, was applied to 
the direct results of titration. The record of Table IV 
shows plainly that excellent results may. be obtained 
very rapidly in the reduction of vanadic acid with the use 
of an electrolytic copper anode in the electrolytic cell, and 
correction with silver sulphate for over-reduction, in the 
manner described. 
TABLE IV. 
Reduction of Vanadic Acid by means of Electrolytic Copper in 
the Electrolytic Cell and Correction by Silver Sulphate. 


V2.0; V.0; Revolu- Approxi- 
taken as found by Period tions of mate 
ammonium KMnO, of anode: strength 
vanadate (corrected)* Error reduction number of current 
grm. germ. erm. min. per min. amp. 
0-0784 0782 —:0002 3:5 800 2 
0-0773 ‘OT75 +-0002 3:9 800 2 
0-0782 0784 +-0002 30 800 2 
0-0776 0778 +-0002 30 800 2 


* 0-20 em.* KMnO, solution. 


Reduction of Vanadic Acid by Zinc.—As is well known, 
the reduction of vanadic acid in sulphuric acid solution is 
easy and in the Jones reductor action may be readily 
pushed to the stage of vanadium dioxide, V.,0,.° It is to 
be expected, therefore, that the reduction by means of the 
rotating cylinder of zine will be rapid without the aid of 
the electric current; nevertheless, in our earlier experi- 
ments with this device it was found that the dimensions of 
the rotating cylinder must be considerable in relation to 
the volume of liquid in order that the stirring of the liquid 
may be sufficient to bring about the reduction with rapid- 
ity. For example, at the end of seven minutes the 
vanadic acid corresponding to 0-1 grm. of the ammonium 
vanadate in the hot sulphuric acid solution was not com- 
pletely reduced to the condition of the tetroxide, V,O,, by 
the action of a rod of zine 0-5 em. in diameter, making a 


® Roscoe, Ann. Chem. Suppl. vi, 77, 1868; Glasman, Ber. d. chem. Ges., 
38, 600, 1905; Gooch and Gilbert, this Journal, 15, 389, 1903; Gooch and 
Edgar, ibid., 25, 233, 1908; ibid., 25, 322, 1908. 


Am. Jour. Sct.—FourtH Serigs, VoL. XLVI, No. 272.—Aveust, 1918. 
15 


Oe SS eee > 


434 Gooch & Scott—Determination of Vanadic Aga 


thousand revolutions per minute and exposing a reaction 
surface of about -9 em.” in 80 em.? of liquid; on the other 
hand, under similar conditions, the reduction passed the 


_ stage of the tetroxide within two minutes when the 


diameter of the cylinder was 2 em., and the exposed sur- 
face about 25 cm.? In the experiments to be described 
the zine cylinder was cast from the best commercial spel- 
ter in the form of a hollow cylinder, closed at one end, 
having a diameter of 2 cm. and a length of 9-5 em. In use, » 
this cylinder was immersed to a depth of about 4 em. and 
exposed an active surface of about 25 ent2 It was 
attached to the rotating axis by means of a rubber stop- 
per. At the end of the process of reduction the solution 
was diluted to a volume of 250 em.?, heated to boiling, and 
titrated with standard permanganate. The correction in 
blank for the materials used, which proved to be regular 
and amounted to 0:18 cm. of the permanganate solution, 
was applied to the titration figures. The results of 
determinations of the rapidity of reduction made under 
the conditions indicated are given in Table V. The 
details of these preliminary experiments show that the 
rapidity of the reduction depends upon the initial tem- 
peratures, as well as upon the rate of rotation and the 
volume of the solution, but that it makes very little dif- 
ference whether the zinc cylinder is simply rotated in the 
solution or is made an anode in the electrolytic cell. 
These preliminary experiments show a considerable 
degree of variation in the rapidity of the reduction, the 
influential factors being chiefly the volume of the solution, 
relative size and rate of rotation of the reducing cylinder, 
and the temperature. The slight advantage in the use of 
the electric current would not seem to warrant its use in 
the reduction of vanadic acid by means of the rotating 
zine cylinder. The following determinations, in which 
over-reduction of the vanadic acid was corrected by the 
use of silver sulphate, were made therefore without the 
aid of electrolytic action. In these experiments the con- 
ditions were the following: viz.—volume of solution 
heated to boiling at the outset, 80 em.*; sulphuric acid 
(cone.) 5 em.*; diameter of cylinder, 2 em.; surface of 
cylinder exposed to action, 25 cm.?; revolutions of cylin- 
der per minute, 850. At the end of the process of reduc- 
tion the solution was diluted to a volume of 250 cm.’, 
treated with silver sulphate (10 cm.? of the saturated 


Gooch & Scott—Determination of Vanadic Acid. 


V.0; 
taken as 


ammonium 


vanadate 
erm. 


0-0781 
0-0782 
0-0781 
0-0777 
0-0782 
0-0780 
0-0781 


0-0779 
0-0775 


0-0779 
0-0775 
0-0780 
0-0776 
0-0776 


0-0777 
0-0777 
0-0778 
0-0780 


0-0776 — 


0-0775 


0-0785 
0-0785 


V205 
found by 
KMn0O, 
(corrected) 

erm. 


0-:0218 
0-0249 
0-:0455 
0-0654 
0-0839 
0-0994: 
0-1140 


0-0782 
0-1208 


0-0746 
0-0882 
0-0664 
0-1155 
0:0917 


0-0678 
0-1070 
0-0756 
0-0918 


0-0399 
0-0751 
0-0790 
0-:0838 


TABLE V. 


Reduction of Vanadic Acid by the Rotating Zine Cylinder: 
Prelinnnary Experiments. 


Error 
erm, 


Period 
of 


min. 


A. 
Reduction at room temperature. 


—0-0563 
—0-0533 
—0-0325 
—0-0123 
10-0157 
10-0214 
-.0-0359 


COM DHMH +H 


Bie 
Reduction begun at boiling temperature. 


10-0003 
0-04.29 
—0:0033 
:0-0107 
—0-0116 


-+0-0379 


10-0141 


—0:0099 
10-0293 
—0-0022 
-0-0138 


—0:0377 
—0-0024 


-.0-0005 
0-0053 


te I ee NO NY NO Nl cl eT NO 


Revolu- 
tions of 
* anode: 


per min. 


800 
800 
800 
800 
800 
800 
800 


800 
800 


800 
800 
800 
800 
800 


800 
800 
800 
800 


300 
800 


800 
800 


Approx- 
imate 


435 


Cone. 


strength H.SO, 
reduction number of current present 


amp. 


LO NOE NOTE NO NOE NO OS) 


em? 


Or Or OV OW Ot Ot O11 


Or O1 Ot O1 Or 


AA YYHHE YHNWNY HH 
OV ON 


solution), filtered from the precipitated silver, heated 
to boiling, and titrated with standard permanganate. 
A correction amounting regularly to 0-18 em.°® of the per- 
manganate solution, as determined in blank, has been 
applied in every case. 

These results indicate the extreme rapidity and accu- 
racy with which vanadic acid in the presence of sulphuric 


436 Gooch & Scott—Determination of Vanadic Acid. 


TABLE VI. 


Reduction of Vanadic Acid by means of the Rotating Cylinder 
of Zinc and Correction by Silver Sulphate. 


VEO: V2.0; | Revolutions of 
taken as found by Period reducing 
ammonium KMnO, of cylinder: 
vanadate (corrected) Error reduction number 
erm. erm. germ. per minute 
0-:0780 0-0799 —0-0001 1 min. 10 see. 850 
0-0777 0:0777 0-0000 be fe lee 850 
0-:0779 0:0777 —Q0-0002 d Eeaiaee | o). 3- 850 
0-0776 00-0777 +0-0001 Aina Ty ace 850 
0-0779 0-0780 +0-0001 1 il Ore 850 


acid may be reduced by the rotating zinc reductor. 
Experiments with an amalgamated zine cylinder showed 
that in this case the reduction proceeds similarly but 
much more slowly. 

It has been shown that while vanadic acid may be 
reduced within a reasonable time, in presence of dilute 
sulphuric acid, by the action of massive silver of consider- 
able area in the boiling solution, the reduction may be 
made very rapid with the aid of rapidly rotating anodes 
of silver or copper in the electrolytic cell, or by a rapidly 
rotating reducer of zinc, over-reduction being corrected 
by the action of silver sulphate. 


Hawkins—Notes on the Geology of Rhode Island. 437 


Art. XV.—Notes on the Geology of Rhode Island; by 
A. C. Hawkrns. 


INTRODUCTION. 


The recent paper by B. K. Emerson,’ covering the 
geology of Massachusetts and Rhode Island, with its 
geologic map, sets forth in a somewhat generalized way 
that of the area included in western Rhode Island. The 
material herewith submitted, largely the results of inves- 
tigations in the latter area by the present writer during 
the years 1912-1916, is in accord in many, important 
respects with Professor Emerson’s conclusions, and may 
serve to furnish certain of the geologic details not 
hitherto available. 


Aciw Ienrous Rocks. 


_ he State of Rhode Island is underlain by a great 

granitic batholith, whose members, now all more or less 
badly sheared, are represented by three principal types, 
the Milford, Northbridge, and Sterling granite gneisses. 
These are biotite granite gneisses of closely similar 
composition,” each with its distinguishing characteristics 
(although certain phases of each resemble the others very 
closely at times), and together or separately they have 
invaded all of the older rocks of this region. The part 
of the granitic mass exposed to the west of the Car- 
boniferous sediments of the Narragansett Basin is in its 
arrangement about as follows: In the northwestern por- 
tion of the State, as far south as the vicinity of Moosup 
Valley, and from thence southeastward toward Hast 
Greenwich, is found the Northbridge granite gneiss, 
covering the western half of Providence County and a 
portion of Kent County; northwest and west of Provi- 
dence, in the eastern half of Providence County, as far 
west as the general vicinity of Woonsocket, and perhaps 
somewhat farther westward (compare Emerson, op. cit.), 
occurs the Milford granite gneiss; and farther south, 
from Kast Greenwich southward toward Point Judith and 


1U. 8. Geol. Survey, Bull. 597, 1917. 

-merson..s, i: and Perry, J. H., U. S. Geol: Surv., Bull. 311, 9-10, 
45-47, 1907; Loughlin, G. F., this Journal, 29, 447-457, 1910; U.S. Geol. 
Surv., Bull. 492, 35-38, 1912. 


438 Hawkins—Notes on the Geology of Rhode Island. 


westward to the Connecticut lne, the Sterling granite 
eneiss is to be seen. Their age relationships are some- 
what obscure, since contact zones are usually either cov- 
ered with glacial debris or occupied by streams or tidal 
estuaries. Some evidence as to age is, however, available. 

Much of the contact zone between the Northbridge and 
Milford granite gneisses is occupied by an acidic granite 
phase like the ‘‘northfieldite’’ of Emerson.2 Yet a mile 
northwest of Oak Valley, R. L., near the road, at a point 
where it makes a sudden detour, just southwest of the 
right-angled cross-roads, a granite gneiss of Milford type 
is in contact with a very dark phase of the Northbridge 
granite gneiss. The former appears to intrude the lat- 
ter and to include portions of it. From these rather 


unsatisfactory bits of evidence it has been concluded that 


the Milford is probably at least slightly younger in age 
than the Northbridge. Between the Northbridge and 
the Sterling, aplites are found to obscure the relations in 
the principal places where exposures are available. On 
Nooseneck Hill, and again just north of Summit, how- 
ever, a coarse porphyritic pink granite gneiss is found to 
be thoroughly interlaminated with a fine-grained gray 
eranite gneiss type. This is interpreted to represent 
the contact zone between the Northbridge and the Ster- 
ling and to indicate that the contact is gradational. The 
Northbridge and Sterling granite gneisses are alike in 
many respects, and it might be reasonable even to suggest 
that the Northbridge type may be a modification of that 
of the Sterling, due to excessive assimilation of basic 
material (hereafter to be more fully discussed), perhaps 
in conjunction with processes of differentiation which 
were possibly set in motion by the latter process. It is 
to be hoped that in spite of scarcity of good exposures the 
relations of these granite gneisses may in time be discov- 
ered in detail. (See further discussion below.) 

East of the Carboniferous sediments of the Narragan- 
sett Basin a similar series of granite gneisses is exposed. 
Exact relationships with the foregoing types are not 
known, but it has been suggested® that certain of the rocks 
closely resemble the Milford and Northbridge type; and 


._ > Emerson, B. K., this Journal, 40, 212-217, 1915. 
4‘Warren, C. H., and Powers, S., Bull. Geol. ‘Soc. Am., 25, 459, 1914. (See 
also Emerson, op. cit.) 
= (a) Emerson and Ee op: cit., 10. (b) Shaler, N. S., Woodworth, 


) Je Be and Koerste, va. Ho Ws. Geol. Surv., Mon. XXXIII, O74, 1899. 


Hawkins—N otes on the Geology of Rhode Island. 489 


while there is little or no evidence of the relative age of 
this granite gneiss series where it is adjacent to the green 
schists of Little Compton, R. I., it is the writer’s opinion 
that they do intrude and include these schists. 

The pre-Carboniferous age of the Northbridge granite 
eneiss is established beyond doubt by its relations to the 
Carboniferous sediments in the area south of Woonsocket. 
From the latter city, a long narrow area of siliceous sedi- 
mentary rocks, the southward extension of the ‘‘ Belling- 
ham Series’? of Warren and Powers,® called by the 
present writer the Woonsocket Basin Series, mentioned 
and outlined in the Report of the. Natural Resources 
Survey of Rhode Island for 1909, and so named, extends 
from the Massachusetts line for a distance of thirteen 
miles into Rhode Island. These sedimentary rocks 
resemble the Carboniferous sediments of the Narragan- 
sett basin (compare analyses in Table I), although they 
are much more thoroughly metamorphosed than the latter, 
being in places changed into biotite schists; but-their age 
is established by a few fragmentary imprints of stems of 
Cordaites, obtained by the writer from a railroad cut just 
west of Woonsocket and northeast of Woonsocket Hill. 
The structure of the granite gneiss bordering this basin, 
as indicated by the dip and strike of its foliation, shows 
that the Woonsocket Basin sediments occupy the eroded 
summit of an anticline with slightly northward pitching 
axis in the Northbridge and Milford granite gneisses (see 
map, fig. 1). For a distance of several miles south of 
Woonsocket the border of the sediments is indistinguish- 
able from the granite gneiss of the side of the basin, the 
former grading into the latter through arkosic beds 
(which are best shown on the west side of the basin just 
north of West Greenville, R.1I.). South of the Waterman 
Reservoir, north of North Scituate, is exposed a great 
thickness of Carboniferous sedimentary arkoses, basal 
beds of the series, containing large amounts of blue 
quartz grains which are especially typical of the Milford 
granite gneiss and at times are also present in the 
Northbridge. The Carboniferous sediments have been 
removed by erosion south of North Scituate, although the 
structural basin persists to South Scituate, where on 
account of the pitch of the anticlinal axis, it disappears.. 

° Warren and Powers, op. cit., 448-449. 


440 Hawkins—Notes on the Geology of Rhode Island. 


ro 
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441 


Notes on the Geology of Rhode Island. 


Hawkins 


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442 Hawkins—WNotes on the Geology of Rhode Island. 


TABLE I. 

Analyses of Carboniferous Sediments from Rhode Island. 
No. 24 25 
SiO oe eee ak 79-77% 61-70% 

DING Raes be ea ab eortar 13-99 27-18 
BeOnc ge ee , 64 8-02 
MeO. ee ie 37 A 
Casa et aieee ee -30 50 

NavO (ta aig ae 2-40 
1 GY en ereree heie ea 2:54 Iegni- 
Ee Oh si aso ned rene ss 38 ~— «tion 
COP ie ea ae ‘06 Loss = 2-90 
Oruite cn te ee None 
it @ ie ieee ee Tr 

100-45 % 100-77 % 
Sp. Gr. 2-690 (porous). 


24, Arkose, Summit of Snake Hill, Harmony, R. I.; Woonsocket Basin. 
A. C. Hawkins. 

25. Shale, Windmill Hill, Providence, R. I.; Narragansett Basin. A. F. 
Buddington. (Composite sample every 2 feet across quarry, exclud- 
ing ottrelitic shales on west wall.) 


The Milford granite gneiss also, together with its 
included quartzites and basic rocks, is clearly pre-Car- 
boniferous. At Nautaconkanut Hill, southwest of Prov- 
idence, for instance, a basal Carboniferous conglomerate, 
exposed along the east side of the hill, contains pebbles of 
eranite gneiss, green schist, and quartzite, plainly derived 
from adjacent outcrops of the latter rocks in the immedi- 
ate vicinity. On the east side of Narragansett Bay, 
arkosic gradations of Carboniferous sediments into the 
bordering granite gneiss are very plainly exposed, as at 
Steep Brook, north of Fall River, and in the railroad cut 
at Tiverton. On Conanicut Island similar conditions 
are found. 

The Sterling granite gneiss is at first much more diffi- 
cult to place as to age relations to the Carboniferous, 
whereas all the contacts along the Narragansett Bay 
front appear to be obscured, largely by a long tidal 
estuary (Pattaquamscott River) which occupies the con- 
tact line. Loughlin’ has maintained that certain coarse 
pegmatites and granites which intrude the Carboniferous 
sediments at Tower Hill and elsewhere in that vicinity are 
probably connected with the Sterling granite gneiss and 
seem to indicate the post-Carboniferous age of the latter. 

7 Loughlin, G. F., this Journal, 29, 450-455, 1910. : 


Hawkins—N otes on the Geology of Rhode Island. 443 


It should be noted, however, that similar pegmatites also 
cut the Sterling as freely as they do the sediments (op. 
cit.). Such intrusions of both the granite and its border- 
ing invaded rocks does not destroy the possibility that the 
pegmatites may be a late phase following the intrusion 
of the main portion of the Sterling batholith. The peg- 
matites, however, seem quite free from gneissic shear 
effects similar to those in the Sterling. Intrusion after 
solidification of the Sterling batholith would naturally 
appear in strongest development along its border, 
especially if there were some faulting along that border, 
as there may have been in the vicinity of Tower Hill. 
These pegmatite and granite dikes, as suggested by Pro- 
fessor C. W. Brown, may well be more easily supposed to 
be contemporaneous with the Westerly granite intrusion 
(post-Sterling) than with the Sterling granite gneiss 
itself; then, too, a small dike of granite similar in type to 
the Westerly granite, to which the writer’s attention was 
called by Professor Brown, intrudes the Carboniferous 
sediments at Hamilton, just south of the point where the 
trolley track intersects the highway. If actually con- 
nected with the Westerly intrusive granite sills, this dike 
would establish the post-Carboniferous age of the West- 
erly granite. Additional and seemingly conclusive evi- 
dence of the pre-Carboniferous age of the Sterling gran- 
ite gneiss is furnished by the following field evidence :— 

A few years ago the Natural Resources Survey of 
Rhode Island (with which the writer was at that time 
working in the field), in the course of work in the west- 
ern part of the State, made careful records, under the 
direction of the Superintendent, Professor Brown, of 
dips and strikes of gneissic foliation of the various out- 
crops of granite gneisses and associated rocks of the area. 
In spite of scarcity of good outcrops, and the obscurity of 
data caused by the extreme metamorphism, many good 
readings were made and recorded. These the writer, in 
the course of this present work, subsequently plotted, in 
addition to other, personal, observations in the north- 
western portion of the State. The Sterling granite 
eneiss is a rock whose gneissic character is pronounced 
and widespread, in Rhode Island as well as in eastern 
Connecticut (a point not noted by Loughlin), giving it a 
banded structure, which, whether due to flowage or 
regional metamorphism, or both, is definitely connected 


444 Hawkins—Notes on the Geology of Rhode Island. 


with a pitching geo-synclinal and -anticlinal structure of 
Alpine proportions in southern and western Rhode Island 
(see map, fig. 1). The largest and most clearly defined 
fold in the granite, concerning whose anticlinal or syn- 
clinal nature no conclusion can be reached, on account of 
insufficient and ill-defined exposures, curves sharply 
around the resistant mass of the Preston gabbro in the 
adjacent part of Connecticut. The latter gabbro mass is 
included in the granite gneiss; hence the observed phe- 
nomena might be attributed to actual flow of the granite 
about the inclusion, or to later shear effects about the 
resistant gabbro body during regional metamorphism. 
The present writer favors the latter hypothesis because 
the foliation in the granite gneiss seems to be connected 
with the presence of feldspar phenocrysts and augen best 
explained as secondary in origin due to such regional 
deformation. If this latter supposition be true, then a 
kind of deformation greatly different from and probably 
vastly older than the folds. of the Appalachians to the 
westward is indicated. This deformation swings east- 
ward toward the Narragansett Basin; it then turns 
northward and extends in this direction through northern 
Rhode Island and into Massachusetts, and northeastward 
apparently to Boston Bay, forming a complicated series 
of synelinal and anticlinal folds, one of the latter, after 
deep erosion of the mountain mass in pre-Carboniferous 
times, being filled with the Carboniferous sediments of 
the Woonsocket Basin. It appears that the Carbon- 
iferous sediments of the Narragansett Basin were sim- 
ilarly laid down at this time in a more deeply and widely 
eroded structural basin between the mass of deformed 
granites just described and the very similarly deformed 
eranites of the eastern side of the Narragansett Basin. 
Along the foliation caused by the deformation the West- 
erly granite’ found its way upward, the intrusion fol- 
lowing an east-west line along the Connecticut and 
Rhode Island shore and appearing probably in the small 
north-south granite sill at Foster, and farther north, and 
possibly in the vicinity of a small outcrop of a oranite of 
similar appearance on the Rhode Island-Massachusetts 
line. The Westerly granite is massive and does not 
share in the gneissic structure which is so typical of the 


8For a new analysis of the Westerly granite, see Table III, analysis 
no. 23. 


Hawkins—Notes on the Geology of RhodeIsland. 445 


Sterling and the Northbridge, and forms welded contacts 
at times across the gneissic banding of the former. But 
the field evidence shows clearly that the enormous pre- 
Carboniferous deformation, above described, affected the 
Sterling, Northbridge, and Milford granite gneisses all 
alike, together with the ancient quartzites and basic rocks 
included in them. It is therefore indicated that all of 
these granite gneisses are of pre-Carboniferous age. 

Loughlin has sought to demonstrate the post-Car- 
boniferous age of the Northbridge granite gneiss in 
northeastern Connecticut, stating that it intrudes the Put- 
nam gneiss, which he considers to be Carboniferous,® 
since it ‘‘has been traced northward into Massachusetts, 
where it is represented by the Bolton gneiss. This rock 
at Worcester, Mass., has been shown by Perry and 
Emerson to le conformably with quartzite and fos- 
siiferous phyllite of known Carboniferous age, and is 
regarded by them as Carboniferous.’’ But geological 
conformity seems to have little value in this region as a 
means of establishing identity of age. This is brought 
forcibly to our attention by the discovery of Carbonifer- 
ous sediments on the eastern slope of Woonsocket Hill, 
in perfect apparent conformity with the finely exposed 
white quartzite of Cambrian or possibly earlier age 
which forms the backbone of the hill. Moreover, the 
writer, as already stated, has found the Northbridge 
eranite gneiss in pre-Carboniferous relations along the 
Woonsocket Basin, and has followed it from thence west- 
ward through the northwestern part of Rhode Island into 
Connecticut, throughout which area, though the outcrops 
are widely scattered and the granite gneiss is modified in 
different ways, it preserves its essential characteristics. 
Ata point a mile south of the hamlet of West Gloucester, 
R. L., on the Putnam Pike, at the base of the southwestern 
slope of a hill of Northbridge granite gneiss, the latter 
may be seen as apparently well-defined sills in a quartz- 
ite. This quartzite is the Plainfield quartz schist,!° which 
Rice and Gregory" regard as ‘‘only a prominent and 

° Loughlin, G. F., Conn. State. Geol. and Nat. Hist. Surv., Bull. 13, 146- 
148, 1910. This formation is mapped by Emerson (op. cit., 79) as gneiss 
of ee Age Undetermined. ’’ 

Westboro (‘‘Grafton’’) quartzite of Emerson, which he finds to le 
unconformably upcon the Northbridge granite gneiss. 


“ Rice, W. N., and Gregory, H. E., Conn. State Geol. & Nat. Hist. Surv., 
Bull. 6, 134, 1906. 


446 Hawkins—Notes on the Geology of Rhode Island. 


clearly marked variation of the Putnam formation;’’ 
which invades Rhode Island from the west in a semicireu- 
lar area not more than a mile long and half a mile wide. 
‘‘ All igneous rocks of the district occur as intrusions in 
the Putnam gneiss, and this formation is therefore older 
than the various dikes, sheets, pegmatite veins, and igne- 
ous masses found associated with it’’ (op. ecit.). ‘The 
abundance of sheets of Sterling granite gneiss intruded 
into the Putnam formation’’ is especially emphasized; 
the same relationships obtain at Preston, Connecticut, 
farther south. The Putnam gneiss and associated quartz- 
ites of the Plainfield series are hence older than the Ster- 
ling and Northbridge members which here compose the 
great granite batholith by which they are surrounded; 
and for this reason they must be pre-Carboniferous in 
age; in fact the writer believes that this whole sedimen- 
tary series, including quartzite and gneiss, belongs among 
the rocks of vastly more ancient origin (which may be of 
Cambrian age or may possibly belong to a still older - 
series like the Grenville? but whose age, in the 
absence of fossils or other conclusive evidence, remains 
unknown), represented by the quartzites, limestones, 
ereen schists, and gabbros (the Blackstone series), pres- 
ently to be described. Through intense metamorphism 
the basic rocks and the Carboniferous sediments have 
locally been altered so as to approach each other in 
appearance and mineral composition; by intrusion the 
Carboniferous shales of Wakefield, R. IL, have been 
changed into hornblende schists, and by shearing in the 
Woonsocket Basin they have become mica schists; fun- 
damental changes of this kind are such as to render 
correlation difficult by lithologie characteristics alone. 
Thus, for instance, there is little evidence to show 
whether the dark inclusions in the Westerly granite are 
Carboniferous in age or much older; (the writer, on 
account of facts observed in the field, favors the 
latter opinion). 

A part of the southern portion of Conanicut Island is 
underlain by a granite which bears a strong resemblance 
to the Sterling granite gneiss to the west!®; phenocrysts 


derived from it are found in the adjacent Carboniferous 


72 All classified together as ‘‘Algonkian?’’ by Emerson (idem). 
8 Loughlin, G. F., U. 8S. Geol. Surv., Bull. 492, 134, 1912. 


Hawkins—Notes on the Geology of Rhode Island. 447 


arkose,'* thus proving it to be ‘‘vre-Carboniferous.’’!° 
Similar granites are found at Mount Hope, in Bristol, 
and at Common Fence Point, on the northern end of 
Agquidneck Island. 

At three points along the southern Rhode Island coast 
there are exposures of granite of a different and perhaps 
later type. A very coarse reddish biotite granite with 
white feldspars underlies Sakonnet Point. It shows 
spots of dioritic appearance, inclusions, or due to differ- 
entiation. It cuts chlorite schist and is cut by aplite and 
minette. It becomes more gneissic eastward. Contact 
relations with surrounding formations are not exposed. 
A granite of closely similar appearance is extensively 
exposed at Newport.'® Again relations are concealed. 
A similar state of affairs exists at the headland of Quo- 
nochontaug, which is formed of a coarse red biotite 
granite, cut by heavy pinkish pegmatite dikes. 

Emerson and Perry" favor ‘‘the early Carboniferous 
age’’ of the East Greenwich granite group; vet ‘‘there is 
indication of a blending of the (granite porphyry) 
breccia upward with the ordinary Carboniferous con- 
glomerate.’’ This is taken to ‘‘suggest the idea that 
they are the result of an eruption of tuffaceous material 
rather than the result of slow erosion on the surface of 
the laccolith,’’ the fragments seeming ‘‘to have been car- 
ried along and to have been cemented by a small quantity 
of the granite porphyry.’’ However, ‘‘the recent dis- 
cussions of Barrell, Mansfield, and others on the conti- 
nental transportation of unaltered feldspathic material 
in semiarid regions suggests another explanation of 
the fresh granite pebbles in the conglomerate’’ (op. 
cit.). ‘‘The conclusive evidence seems to be lacking”’’ 
(Foerste)!®; but ‘‘the succession of events becomes 
simpler if we assume that the porphyries and micro- 
granites of the series formed the surface of a rather 
thinly covered batholith, which was just exposed by 
erosion in early Carboniferous time.’!7 The present 
writer agrees with the latter statements. The contact 
of the East Greenwich granite group with the adjacent 

te Shaler, Woodworth, and Foerste, op. cit., 233. 

* Hmerson and Perry, op. cit., 46. 

16 Shaler, Woodworth, and Foerste, op. cit., 316. 


17 Op. cit., 69. 
*8 Shaler, Woodworth, and Foerste, op. cit. 


448 Hawkins—Notes on the Geology of Rhode Island. 


‘‘pre-Cambrian’’ Northbridge gneiss is mapped by 
Emerson and Perry as an intrusive one, the Hast Green- 
wich granites being the younger. Relations with the 
Milford granite gneiss are not discussed by them. The 
field relations are obscure, but dikes of aplitic and gran- 
itic material which cut the granite gneisses in the vicinity 
of Riverpoint and Arctic might perhaps be referred to 
the Kast Greenwich group. 

Felsites are not prominent in this State, and yet small 
occurrences are present in at least two places. In the 
adjacent area of South Attleboro, Massachusetts, they 
are extensively developed, being associated with Carbon- 
iferous sediments and diabase. At Diamond Hill, Cum- 
berland, R. I., a considerable mass of dense felsite has 
been largely replaced by vein quartz,’® but.fragments of 
it are still plainly visible. There is also present on the 
crest of this quartz mass a small area of unknown extent 
underlain by a coarse biotite granite similar in appear- 
ance to that exposed in the quarries a mile farther west; 
relations of granite and vein quartz are not exposed. 
Again on the northwest slope of Bald Hill, in Scituate, in 
local drift, are found narrow red felsite dikes cutting a 
eranite gneiss. This latter occurrence extends the zone 
of rhyolite occurrences in Rhode Island southward a 
little farther toward the far-away field of similar rocks 
at South Mountain, Pennsylvania. 

A very well-defined zone extending from Wakefield 
through Newport to Sakonnet Point is occupied by pre- 
Carboniferous green schist, quartzite, limestone, and 
oranite, cut by prominent intrusions of pegmatite, 
eranite, diabase, gabbro, and minette, and bordered on 
the north and possibly also on the south by sediments of 
Carboniferous age. The writer suggests that this zone 
of ancient rocks may represent an elevated block or 
horst, separated by fault zones of nearly east-west strike 
(probably pre-Carboniferous in age) from adjacent 
blocks which have fallen away on the north and south. 
Within this zone of disturbance, at various times, the 
numerous intrusions have found their way upward. It 
is in line with the Westerly granites and pegmatites, also 
parallel to the coast line. 


19'‘Warren, C. H., and Powers, S., Bull. Geol. Soc. Am., 25, 472, 1914. 


Hawkins—N otes on the Geology of Rhode Island. 449 


Basic Ignzous Rocks. 


Of basic igneous rocks there are three distinct types in 
the region herein studied, viz: Green Schist, Diabase, 
and Gabbro. 

(1). The Green Schist. 


_This occurs at several localities within the area under 
consideration, namely, in the Blackstone Valley, north- 
west of Providence, and in Johnston and Cranston, west 
of Providence, where it is associated with white quartz- 
ite, as already mentioned; in similar relations at 
Premisy Hill, a small eminence 3 miles west-southwest 
of Woonsocket; and in several scattered exposures 
between West Greenville and Primrose. In the Black- 
stone Valley it has been mapped by Emerson and 
Perry (op. cit.) and assigned to the Cambrian (Marl- 
boro formation). Other writers of earlier (Shaler, et 
al., op. cit.) and later date (Warren and Powers, op. cit.) 
would place it in the pre-Cambrian. (Compare also 
Emerson, op. cit.) On account of lack of evidence, 
determinations of the age of the green schist-quartzite 
series have been made from lithologic similarity of these 
rocks to others not visibly connected with them but of 
known age (the Cheshire and Westboro (‘‘Grafton’’) 
quartzite; compare views of Emerson and Perry (op. 
cit.) with those of Warren and Powers (op. cit.)). 
(‘‘Aleonkian?’’ of Emerson). There are several local- 
ities in the southern part of the State where the occur- 
rence of green schists or slaty rocks has repeatedly 
attracted attention. They have been enumerated by 
Foerste (op. cit.) as follows: 

At Church’s Cove, west of Tiverton Four Corners, and 
southward to Little Compton, a series of greenish shales 
is exposed, associated with rusty limestones intersected 
by numerous quartz veins. Green schists and slates on 
Sachuest Point are described, also those on Conanicut 
Island south of Jamestown, in the vicinity of the 
Dumplings, and those at Newport. At least two of these 
localities show the greenish rocks only in the most uncer- 
tain relations with the known Carboniferous sediments 
and the other adjacent rocks, so that little is known of 
their age, except that they are probably for the most part 
pre-Carboniferous. The altered dioritic ‘‘dikes’’ of 
‘‘Paradise,’’ near Newport, and a hornblende and 

Am. JOUR. ree Eee Series, VoL. XLVI, No. 272.— Aveust, 1918. 


450 Hawkins—Notes on the Geology of Rhode Island. 


actinolite schist along Sin and Flesh Brook, southeast of 
Tiverton, are apparently of similar age. 

In the extreme northern part of the State, at Round 
Top, a fissile, closely plicated muscovite schist is asso- 
ciated with quartzite. The schist carries chlorite, and 
also garnets of small size and rarely black tourmaline. 
It is probably also closely related to the green schist 
series, being mapped as part of the Westboro quartzite 
by Emerson. 

The green schists are quite generally gabbroid in com- 
position (see analyses, Table II), and in appearance and 
behavior, though badly sheared, suggest ‘‘the derivation 
of some part of the material from basic tuffs’’ (Kmer- 
son and Perry, op. cit.), the tuffs being interbedded with 
the quartzites. Interlayering of the two kinds of rock at 
the contacts also affords for these authors additional evi- 
dence of sedimentary origin for the schist. There are 
a few beds of the green schist in the quartzite, however, 
which seem to actually represent intrusive sills in ht- 
par-lit injection. One of these appears as a breccia of 
quartzite fragments in green schist matrix at Violet Hill, 
Manton (underneath the perched granite bowlder on the 
hill just north of the Manton Avenue quarry); and thin, 
ramifying, sill-like layers of schist in a quartzite at a 
small exposure southeast of Oak Valley, in North Smith- 
field. The appearance of large, isolated masses of 
quartzite, too large and isolated to represent conglom- 
eratic bowlders, seems also to point toward actual 
intrusion. 

The schists in their coarser phases exhibit a mass of 
long green actinolite blades intermingled sometimes with 
areas of granular or saccharoidal feldspar. An extreme 
case of the production of secondary feldspars of this kind 
is in the rock exposed along the highway at West Green- 
ville, where it is filled with closely set pseudo-phenoerysts 
of a saccharoidal feldspar near albite in composition, 
lath-shaped, some attaining a size of 1 em. X 3 em., and 
showing roughly parallel arrangement simulating flow 
structure. About two miles north of this latter place 
the green schist grades into a true gabbro. In contrast 
to this, the gabbro at Woonsocket (Huntington Avenue) 
contains inclusions of green schist surrounded by reac- 
tion rims. 


Hawkins—Notes on the Geology of Rhode Island. 


TaBLE II. 


Analyses of Basic Igneous Rocks from Rhode Island. 
(A.) Green Schists. 


gla 12 
See. ke 66-58 43-60 
LDS Se ees 13-04 26-90 
[ET Sa a aa 7:08 3-20 
2) eS Sea ieee 1-40 8-60 
“9 Ses ee 1-01 2-51 
lg 1 gis ae 2-76 10-83 
GS ee ee 5-26 1-75 
4 3-44 2-52, 
, 180) Se errs -16 -64 
os i era ne Sahay. 
PURO Sere es eee ss oan ©. 07 
a 2 Loe 
ag Sosiccie 3a, xe .c 
100-73 100-62 
Se Gate Mees. 2.844 


13 14 
50-87 46-39 
19-47 18-32 

4.29 6-44 

7-88 6-82 

2-85 4.66 

8-99 12-58 

2-21 1-98 

2-57 1-31 

73 73 

‘75 43 
ee AMY 

-10 12 

et -25 


100-71 100-03 


451 


15 
41-62 
13-16 

6-71 

4.48 

8-88 
17-71 

1-42 

1-08 

72 

4-76 

-14 


100-68 


11. Manton, R. I. (Unaffected by granitic intrusion). A. C. Hawkins. 


12. Manton, R. I. (Largely affected by intrusion). 
13. Neutaconkanut Hill, Thornton, R. I. (Slightly affected). 


kins. 


14. Berkeley, R. I. (Unaffected by granitic intrusion). 
15. Berkeley, R. I. (Somewhat affected by intrusion). 


Local drift; porphyritic augites. 


TABLE II. 


Analyses of Basic Igneous Rocks from Rhode Island. 


4 
49.57 
12-40 

3-58 

~ 7-04 
5-76 
15-86 
2-13 
2-29 

— 48 
-02 


5 
44.36 
18-15 

5-46 
11-62 


Gabbros and Related Types. 


6 7 8 


44.33 48-43 51-86 
20-58 15-76 15.72 
1-29 Ie Paes Bi Me 
11-39 7-68 14-87 
4.79 6-34 5-50 
7-40 10-19 7-20 


2-94 2-22 
37 1.48 
-08 -56 
-12 -04 
5:00 3:00 2-75 
68 2.34 


A. F. Buddington. 
A. C. Haw- 


A. C. Hawkins. 
A. C. Hawkins. 


————. —_—__—_. ae _—__ ————_—__. —————— oOo —_—__. —___. i 


ieee —eeeeeeesee eee 
—_—_—_. 


* P.O, by A. C. H. 


2.970 


(B.) 
1 2 3 
BIO,” hi 22-3 46-48 50-48 
Al.O, .... 5:26 15-69 21-26 
He,0, 1... 14-05 7-10 2-05 
FeO ..... 28-84 8-66 6-86 
MgO .. 16-10 2-74 2-15 
CaO 1-17 11.42 7-23 
Na,O 44° 2.14 3-03 
OF ate: -10 -70 2-07 
H,O4. . 3 -20 83 
H.0 42 03 40 
dig OS oe 10-11 3-80 2-00 
OS cceeers -02 -28 95 
P50; -02 -11 98 
Me certs 30 = 80) 08 
MnO -43 Tr Tr 
100-74 100-15 100-53 100-32 100-47 
Sp. Geigy. 13-92 3:086 2-928 


3-112 


3-203 2-962 


9 10 
46-11 39-30 
14-52 15-58 

2-20 2-65 
4.51 4.62 
5:73 4.00 
7-82 13-49 
1-29 1-27 
3-84 4.03 
2-90 2-28 
wat 37 
-84 15 
7-32 7-21 
2a. 5 t4. 
1-37 -39 
Ty Tr 
99-65 100-25 
2-904 2-961 


452 Hawkins—Notes on the Geology of Rhode Island. 


Norms of the Basic Igneous Rocks Analyzed (Table II). 


it 2 3 a 5 6 7 
Oar tee nee ee see fe 5-79 > Ao: Pips Soe rae 
ON) ie shag ee 56 4.24 12.58 13-74 10-29 2-30 9.97 
AND eee 3-67 19-45 25-82 18.32 20-35 24.90 7-94 
SANTI er espa 5-56 34.39 30-81 18-01 29-50 32-93 33-25 
Dis eee hie 20-91 Sipe sere 16-24 ses 6-68 
Jehigine pee oe ei cietece See 13-28 echelons aa hae 
TTS 5 hoes faye he ee eiees Sahoe eee Nigene 3 sais ane 17-64 
Olen ray 45-70 8-09 Eee 19-76 13-23 15-50 9.14 
AMES: Bec Beet 20-65 A ae 2-65 5-24 7-38 1-86 3-14 
Ua Vegan 19-00 7-75 3-80 ewe. 1-71 9.50 6-26 
PION Cae 1-15 ee seis 2-55 aaa Seg Rae 
D9 ORR ie ree os oc dee 2-02 aaa 
ASS) Ss kei iat 4.50 yh 21-76 
BOT eco as coun weds He 3-25 gare sfumleee 
Grains hie emia: Aare Cee 11-50 
Spinel ©... 516 43-50 Aaa Bal saa Hues Nie digas: APE 
Calciters a cuyey ee: 67 aes 62 1-30 1-51 5-98 
Classification of the Basic Igneous Rocks Analyzed (Table II). 
1. Peridotite, rhodose, V.3.1.2. Iron Mine Hill, Cumberland.* C. H. 
Warren. 
2. Gabbro, auvergnose, II1.5.4.3. Ironstone Reservoir, Mass.t A. C. 
Hawkins. 
3. Gabbro (Hybrid), shoshonose, II.5.3.3. Woonsocket, R. I. A. OC. 
Hawkins. 
4, Gabbro, oronose-auvergnose, ITI.5.4.2. Pascoag, R. I. A. C. Hawkins. 
5. Gabbro (Actinolite Schist), auvergnose, III.5.4.3. West Greenville, 
R. I. <A. C. Hawkins. ao 
6. Gabbro, near auvergnose, III.5.4.5. Moosup Valley, R. I. A. C. 
Hawkins. 
7. Olivine Diabase, oronose-auvergnose, II1.5.4.2. Snake Den, R. I. A. 
C. Hawkins. 
8. Diabase, South Attleboro, Mass. Chemist, Am. Steel and Wire Co. 
9. Minette, Conanicut Island, R. I. J. P. Iddings. 
10. Minette, Sakonnet Point, R. I. A. C. Hawkins. 


The last four rocks were probably not fresh. 


* Compare Emerson (op. cit., 183 and 185). 
+ Compare Emerson (idem, 170). 


(2). The Diabases. 


The development of diabases is strongest toward the 
northern border of the State; western Rhode Island is 
free from them. They show a tendency to follow prom- 
inent joint-planes which mark lines of structural weak- 
ness, arranged in several zones with a north-south or 
northeast-southwest strike. One of these appears to be 
along the western margin of the Carboniferous basin at 
Woonsocket and southward, while another les a few 
miles to the eastward, and still another extends south- 
ward from Cumberland Hill. Most of these diabases, 
both dikes and sills, are not very large, the most exten- 
sive ones sometimes attaining a length of a quarter of a 


Hawkins—Notes on the Geology of Rhodelsland. 458 


mile, with a width varying from one or two inches to 50 
or 60 feet. 

The diabasic dikes are of four distinct ages, as follows: 

First, dark-colored dikes, now hornblende schist, in the 
_ Harris quarries at Limerock.*° This type cuts limestone 
of supposedly Cambrian or pre-Cambrian age (Smith- 
field limestone), and is in turn intruded by fine-grained 
aplitic granite offshoots, which probably belong to the 
adjacent Milford granite series. ‘This hornblende dike 
material is the ‘‘odinite’’ of Kmerson and Perry (op. 
eit.), and is immediately post-shearing. 

Second are the diabasic sills of South Attleboro, Mas- 
sachusetts,1 just across the Rhode Island line, which 
rarely appear as dikes. They are somewhat later than 
the red Carboniferous beds of the Attleboro area (Wam- 
sutta group), being perhaps post-Carboniferous. But 
these traps, which cut felsites, are now found by C. W. 
Brown to be definitely cut by felsites of another age, a 
relationship which has not been shown in the earlier 
work (op. cit.). 

Third are placed the minette, or ‘‘mica trap’’ dikes, 
apophyses corresponding to mica syenites. Dikes of this 
rare rock have been described as occurring on Conanicut 
Island, R. 1.2. The latter writer, in the paper just cited, 
gives an analysis of the rock (here quoted, see analysis 
No. 9, Table II). There is also a new dike, of the same 
nature, now to be reported from Sakonnet Point, some 
fifteen miles farther east. This is a five-foot dike with a 
strike of N. 30° W. and a dip of 75° W.; it cuts coarse 
red granite of unknown age. Attention was originally 
called to this dike by Mr. H. I. Richmond. The deter- 
mination of phosphoric acid in the minette of Conanicut, 
here stated for the first time (see analysis No. 9, Table 
II), shows it to contain only a very small amount. The 
minette of Sakonnet, however, is unusual in containing 
about 12% of apatite, forming large idiomorphic crystals 
which are very prominent in the microscopic section. 
(Also-see analysis, No. 10, Table II.) These minettes 
have been described as cutting granites and Carbonifer- 
ous sediments at Conanicut. They have also recently 
been found to intrude the green schists, at a point 


°° See Emerson (idem, 185). 
*t Shaler, Woodworth, and Foerste, op. cit., 152. 
” Collie, G. L., Trans. Wis. Acad. Sci., 10, 36, 1895. 


454 Hawkins—Notes on the Geology of Rhode Island. 


just south of Jamestown. They are in turn cut by 
quartz veins. 

Fourth are fine-grained dikes of diabase, usually in 
vertical or steeply dipping position, and of the type 


usually referred to the Triassic. The necessary proof . 


of exact age is lacking.. They are all in the northern 
third of the State, occurring, together with the adjacent 
intrusive sills of Attleboro, Massachusetts, already men- 
tioned, within an area about 12 miles square, lying to 


the northeast, north, and northwest of Providence, and 
including Cumberland Hill and Woonsocket. To this 


type belong the 60-foot dike at Woonsocket (cutting Car- 
boniferous sediments), the 10-foot one at Snake Den (in 
granite gneiss), the 8-inch one at Miner’s Crossing 
(in green schist), the narrow one at Cumberland Hill 
(intruding gabbro), and others at Wionkhiege Hill, 
Primrose, and in the cut for the new State road on Law- 
ton Hill, west of Thornton. Usually these diabasic dike 
rocks show abnormal mineral constituents resulting from 
entire or partial solution of portions of acid terranes 
adjacent. Daly finds this process often occurring with 
the same result,?? and Powers** has quite fully discussed 
the nature and origin of such foreign materials. The 
large diabase dike at Woonsocket, 60 feet or more across, 
encloses relatively enormous quantities of angular and 
rounded fragments of quartz, granite, diorite, and Car- 
boniferous shale. The inclusions in this dike have been 
observed to be at times four feet long by two feet wide, 
and the foreign materials frequently make up as much as 
50% of the total rock mass. Dikes in the region to the 
southward and eastward of Woonsocket show similar phe- 
nomena to a more limited extent. One dike (that at 
Snake Den in Johnston) is filled with microscopic cav- 
ities (‘‘Kugel’’ Structure). 

These rocks are typical olivine diabase, of which one of 
the best developed, that at Snake Den, has been selected 
as the type, for microscopical and chemical investiga- 
tion. A chemical analysis of it is given (see analysis 


No. 7, Table II). This diabase shows two periods of: 


crystallization during cooling, as is typical of this 
rock type. The phenocrysts are olivine, labradorite 
(Ab,An,), and pyroxene. The groundmass is composed 


3 Daly, R. A., ‘‘Igneous Rocks and Their Origin,’’ 1914. 
* Powers, S., Jour. Geol., 23, 1-10, 166-182, 1915. 


Hawkins—N otes on the Geology of Rhode Island. 455 


largely of lath-shaped labradorites of medium composi- 
tion, near Ab,An;, augite, biotite, and ilmenite. The 
Rosiwal test yields percentages as follows: 


Ab,An, = 47-75% 
AbsAn e157 -51 
Pyx = 16:29 
Ol ==) OUD 
TI == 403 02 


Caleite = 13-92 


The unusually high percentage of TiO, indicated by the 
analysis is notable, and the large amount of CO, in ecal- 
cite, which shows that the rock is not fresh. 


(3). Lhe Gabbros. 


There are also several stocks of predominantly gab- 
broid nature, included in the granite gneisses.2> These 
gabbro masses are often lenticular in shape and widely 
separated in position. Such basic rocks are shown in 
scattered areas throughout the northern part of Rhode 
Island, and to some extent in its southern, western, and 
even in its eastern parts. The most important ones are 
at Cumberland Hill, Woonsocket, Ironstone Reservoir, 
Pascoag, Chepachet, West Greenville, Smith and Sayles 
Reservoir, Sneech Pond, Moosup Valley, and at Pres- 
ton?® and Wequetequock,?’ Connecticut. They are dis- 
tinetly pre-Carboniferous, as indicated at the gabbro 
outcrop at Huntington Avenue and Gaskill Street, Woon- 
socket, which lies in the Carboniferous basin. Their pre- 
cise age 1s unknown, although they are doubtless very 
old, being older than any of the granite gneisses in the 
batholith which underlies this region. They now appear 
only in scattered fragments and groups of fragments, 
roof pendants*® which have partly sunk in the granite 


** For various reasons, as hereafter enumerated, these gabbros are 
regarded by the writer as original intrusive rocks and not as reaction 
rims of granites. Epidote is formed by reaction of the granite upon 
intrusion against the basic rock, as described below (see discussion of 
the contact metamorphism). (Compare Emerson, idem, 167-170.) 

7° Loughlin, G. F., U. S. Geol. Surv., Bull. 492, 1912. 

7 Hatch, L. (unpublished thesis). 

78 Daly, op. cit., 100. 


456 Hawkins—Notes on the Geology of Rhode Island. 


batholith, and through subsequent diastrophic action 
have been modified greatly in distribution and shape, and 
in some cases in texture, mineralogical composition, and 
appearance. Exposures now available show them to be 
nearly vertical strips of lenticular sheets, lying in the 
granite gneiss parallel to its gneissic strike and dip 
throughout. This is to be seen at Westerly and at White 
Rock, four miles to the north of the latter place, in a 
small granite quarry. In plan they are evidently of 
lens- or pod-shaped form, similar to that assumed by 
deposits of metallic sulphides in the ancient crystalline 
rocks, as the result of diastrophism; transverse faults 
dislocate the series. (Compare the relative positions of 
the Ironstone gabbro masses, the fault of similar direc- 
tion and throw which traverses the gabbro mass at 
Preston, and the fault with horizontal dislocation of 
approximately two miles which passes through the 
vicinity of Greenville and Wallum Pond.) The phe- 
nomena so observed are closely similar to those recorded 
by Fenner’ as occurring in northern New Jersey. This 
also indicates the relationships and probable shape and 
extent of the well-known peridotite of Cumberland Hill, 
which, as an included fragment rather than a true dike 
or stock, still may be regarded as having a considerable 
downward extent. Its close relationships with the other 
gabbros of the series are more fully discussed below. 
The larger gabbro masses of western Rhode Island 
may be one or two miles long and nearly as wide. The 
rock of these masses is homogeneous, coarse, and almost 
entirely untouched by either intrusion or shearing. 
Apparently it is resistant to both agencies, and the 
granitic intrusions have failed to penetrate far into it. 
The texture of the gabbro is generally allotriomorphie, 
and similar to that of Preston, though certain phases are 
porphyritic, as at Moosup Valley, and diabasic, as in 
parts of the Ironstone Reservoir mass and at Woon- 
socket. Along planes of shearing it becomes hornblende 
or biotite schist, as in the exposures shown south of Pas- 
coag, on the west side of the reservoir. From the larger 
gabbro masses smaller ones, usually in the form of 
long lenticular strips (see map), have separated ; their 
present position and appearance presumably is due to a 
combination of contact action (stoping) and diastro- 
7” Fenner, C. N., Jour. Geol., 22, 594 et seq., 1914. ; 


Hawkins—Notes on the Geology of Rhode Island. 457 


phism on a large scale. The stoping off of strips by the 
granite which everywhere surrounds and invades the 
margins of the gabbro may be seen with great clearness 
just east of the gabbro mass of Pascoag, in the granite 
eneiss ledges at the east end of the dam just south of the 
town. These gabbro strips may be a mile or two long 
and only a few hundred feet wide. Often they are mas- 
sive, but at other times are sheared into hornblende and 
biotite schists. Their present outcrop is partly the 
result of glaciation which has greatly modified the topog- 
raphy, but more largely the result of the resistant nature 
of the rock to other erosive agencies. Each strip of gab- 
bro is marked by a long roche moutonnée, and the granite 
ean often be traced for long distances on either side of it. 


Field Relations of the Gabbro-Green Schist Group. 


The gabbros and green schists of western Rhode 
Island lie in two curving lines, extending across the 
northern part of the State from north to south, the curve 
being convex toward the east (see map). The eastern 
belt consists of basic schists, (related to those in the 
Blackstone Valley to the east), and extends from 
Woonsocket to West Greenville, with a southward repre- 
sentative in the fragment a mile south of Harrisdale. 
This belt of schists has been carried a couple of miles 
eastward by the fault which intersects it at West Green- 
ville. Originally it was only about five miles from the 
western belt of gabbros. The western belt comprises a 
series of coarse to fine-grained gabbros, extending in a 
widening band from fragmentary outcrops near Beach 
Pond and small but typical exposures at Moosup Valley, 
northward to Round Top and Ironstone Reservoir. 
This belt- also is dislocated in its northern portion, ‘so 
that this part appears about two miles to the east of its 
original position. 

The invasion of the granite took place under a thick 
cover of quartzose sediments interspersed with this 
series of basic intrusives and tuffs. Broken fragments 
of the cover, stoped off, became engulfed in the granite 
and were folded with it during the deformation which 
followed and possibly accompanied its intrusion. Subse- 
quent erosion has left probably only the deeper portions 
of the batholith, to give us its history, but the presence of 


458 Hawkins—Notes on the Geology of Rhode Island. 


numerous basic inclusions in the granite of the Westerly 
region, aS suggested to the writer, may indicate that the 
roof of the batholith was lower toward the south; and 
perhaps also that the present coast line may be imagined 
to have resulted from lack of resistance to erosion on 
account of predominant amounts of the weaker basic 
schists in the granite still farther southward. A similar 
lowering of the batholithic roof to the eastward may 
explain the present distribution of exposures of schist in 
the Blackstone Valley and gabbros farther west; or 
downward tilting toward the east (indicated by the atti- 
tude of the sediments in the Woonsocket basin) may have 
caused erosion to expose deeper seated rocks to the 
westward. 

The arrangement of parallel belts already mentioned 
suggests a synclinal or anticlinal structure. Minor 
structures so obscure the larger ones, and exposures are 
so scanty, however, that its exact nature has not been 
discovered. The fact that two rock types on opposite 
limbs of the fold (those at West Greenville and Moosup 
Valley; see analyses) are closely related in chemical com- 
position might be construed as favoring this hypothesis. 

The chemical analyses of the gabbros taken collectively 
(Table IT) show them to be uniformly of very basic types, 
but varying systematically in content of femic and salic 
constituents. The most basic example in the State is 
the peridotite or cumberlandite of Cumberland Hill. This 
may represent the ancient center of igneous activity in 
intrusion. Westward and southwestward from it the 


gabbros steadily decrease in femic content, rapidly at. 


first, then more and more slowly, to Moosup Valley, and 
finally to Preston, Conn. When plotted graphically, the 
line connecting the points representing femic content of 
the various types form a continuous curve (fig. 2). This 
would seem to indicate something of the nature of the 
areal distribution of igneous intrusive activity in west- 
ern Rhode Island before the great granite batholith 
invaded the region. The writer also ventures to suggest 


that the study of related rock types from Cumberland. 


Hill northward into Massachusetts might add further 
interesting facts with regard to this basic intrusive 
series, and ultimately establish proof whereby the geo- 
logic age of the whole peridotite-gabbro-green schist 
series might be established. 


Hawkins—N otes on the Geology of Rhode Island. +459 


Hig. 2. 


10 20 30 40 miles. 
Chemical relations of the Gabbros. 
Fig. 2.—The vertical component in the diagram represents femic content 


in per cent. The horizontal component represents distance in miles from 
Tronmine Hill, Cumberland, R. I. 


Tabulation of Norms of Gabbros of this Group in Rhode Island and 
Vicinity. (See Fig. 2.) 


Point Locality | Classification eal Fem ® Ef P-+O -M A _ Analyst 

A. Cumberland, R. I., peridotite .. 9-79 90-05 9-79 49.25 39.65 1-15% C. H. Warren 
B. Ironstone, Mass., gabbro ...... 49.68 50-32 49.68 24-81 16-18 9.32% A.C. Hawkins 
©. Paseteas he: 1) 2sabbro'').. o.. 2. 57-18 42-82 57-18 39-64 7-37 5.81% A.C. Hawkins 


D. Moosup Valley, R. I., gabbro .. 60-13 39-87 60-13 27-00 11-36 1.51% A.C. Hawkins 
EH. Preston, Conn., Cse. Hb. gabbro 57-10 40-61 57-10 34.43 618 ...% W.A. Drushel 


Sal = salic content. 

Fem = femic content, upon which the curve of fig. 2 is based. 
F — feldspar content. 

P +O = pyroxene -| olivine. 

M = iron ores, including magnetite and ilmenite. 

A = accessory minerals. 


| 
| 
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460  Hawkins—Notes on the Geology of Rhode Island. 


Characteristics of ths Gabbro Group. 


The gabbros when fresh are typical rocks of medium 
size of grain; with increase of hornblende these pass 
into a black rock with bladed structure, usually rather 
coarse. Under the hand lens the coarser gabbros show 
laths of white plagioclase (also sometimes dark-colored), 
hornblende and pyroxene crystals, frequently some fresh 
biotite plates, and black grains of magnetite and ilmenite. 
The microscopic characters of the group are as follows :— 


(1). Diabasic texture with labradorite. 
(2). Graphic intergrowth of magnetite and ilmenite with 


‘biotite and basaltic hornblende. 


(3). Corona structure involving olivine and iron ores with 
rims of hornblende, biotite, and hydrous alteration products. 
— (4). Inclusions of quartz carrying rutile and constantly 
moving bubbles. , . 


The chemical characters of the group are generally 
as follows :— 


Ck). Low: in SiO, Me@,.Na,O;, KO; 2G Eee: 
(2). High in FeO and CaO. : 


Endomorphic and Exomorphic Chemical Changes Due to 
Contact Metamorphism. 


(Production of Hybrid Granites, Pseudo-Diorites, and 
Limestones. ) 


The characteristics of many of the contacts of granite 
with the basic rocks have been mentioned above. In 
other instances, however, a well-defined gabbro, of mas- 
sive, holocrystalline nature, may be surrounded for a dis- 
tance of a mile or more by a complex of hybrid rocks 
resulting from the intimate intermixture of gabbroid 
material with granite, evidently a partial assimilation of 
the basic material by the latter rock. (Compare Kmer- 
son, idem, 173-175.) The injection gneisses of this type 
are light gray, or streaked with wavy light bands of 
granite or material resulting from pneumatolytic effects 
from the latter. Of this sort of occurrence the finest 
example is found at South Foster, of which further men- 
tion will be made. (Compare Dana Diorite of Emerson, 
especially figs., 245 (idem).) 


Hawkins—N otes on the Geology of Rhodelsland. +461 


Near contacts with the basic rocks, and often for dis- 
tances of several miles from visible contacts with large 
masses of basic rock, the intrusive granite gneisses com- 
monly, though not always, have been found to show an 
abnormally dark color, increasing as the contact is 
approached. With this darkening of color, small dark 
fragments of unassimilated basic rock appear,®° scat- 
tered at intervals throughout the granite gneiss. At the 
same time the granite becomes increasingly porphyritic, 
the orthoclase phenocrysts often attaining a length of one 
or two inches. The best example of this phenomenon is 
found in the ‘‘ Absalona”’ type of the Northbridge granite 
eneiss, well shown on Absalona Hill, east of Chepachet.** 
That a real and not inconsiderable change in the compo- 
sition of the granite has actually taken place is plainly 
indicated by the analyses of the granite and green schist 
types (to be more fully discussed; see Table III). The 
granites also apparently have had the power to assimilate 
a certain amount of quartzite and similar acid rocks, 
becoming more acid thereby; but on account of similari-- 
ties of composition of the intruding and intruded rock 
types, the changes in a physical way are certainly not so 
noticeable. 

The result of this assimilation process is seen in the 
field in the widespread production of rocks which are 
both in their appearance and in their physical and chem- 
ical composition intermediate between the gabbro and 
eranite types. Coarse, porphyritic, dark-colored gran- 
ites of almost dioritic aspect are in places extensively 
developed, and appear at first to add much to the com- 
plexity of the geologic situation. (Compare Hybrid 
Rocks, Bowen,*? also analyses 3, Table II, and 18, Table 
Ill.) This is especially true of the Northbridge granite 
eneiss, which is made up of a variety of abnormally basic 
eranite types throughout northwestern Rhode Island. 
It is found in this condition, dark-colored, porphyritic, 
and filled with basic masses, stringers and fragments, as 
indicated on the map, throughout an area bounded on the 
north by the Rhode Island-Massachusetts line, its south- 


°° The orbicular Westerly granite type of Quonochontaug, R. I. (See 
Kemp, J. F., Trans. N. Y. Acad. Sci., 13, 140-144, 1894), is probably 
similar in origin. 

* This is the ‘‘Carboniferous conglomerate’? mentioned by Emerson 
(idem, 229). 

* Bowen, N. L., Jour. Geol., 23, Supplement, 85, 1915. 


462 Hawkins—Notes on the Geology of Rhode Island. 


ern boundary passing through a point south of the 
jyanction of the Putnam Pike with the Rhode Island-Con- 
necticut line, thence southward as far as Moosup Valley, 
and from thence northeastward, its southern border pass- 
ing, apparently, south of N orth Scituate (see map). 
The Milford granite gneiss in the Blackstone Valley- 
Woonsocket region is similarly affected, where it has 
intruded and embayed the margins of the green schists, 
and torn off portions of them. On the east side of Nar- 
ragansett Bay the granite gneisses show the same char- 
acteristics. 3 

The green schists exposed in the region immediately 
west and north of Providence are normally fine-grained, 
greatly sheared rocks of essentially gabbroid compo- 
sition (see analyses of green schists, Table Il). The 
schists ‘‘become coarsely crystalline’’ near contact with 
the granite at Neutaconkanut Hill, as observed by Emer- 


son and Perry (op. cit., 29). Moreover, this coarseness of 


crystallization increases in such measure as to cause the 


- appearance of the ‘‘diorite’’ of the above authors (idem, 


44), which, as a type, on account of its origin, will be 


referred to as the ‘‘pseudo-diorite,’’ a name suggested by 
Professor C. W. Brown, who also first conceived of its 
formation in this way. ‘‘Little or no trace of crushing”’ 


(idem, 44) is far more generally shown in the pseudo- 
dioritic contact zone than in the adjacent schists. The 
resulting rock closely simulates the true diorite in its 
coarse groundmass of short black amphiboles in feldspar 
(idem, 29). Some replacement of secondary pheno- 
erysts has occurred (idem, 30); these phenocrysts are 
either hornblende, as described (idem, 44), or pyroxene, 
as observed in local drift material from Berkeley; these 


latter pyroxenes are nearly equidimensional, measuring 


1 to 2 em. or more in diameter, and showing bright cleav- 
age at 87°. An analysis of this latter rock, which unfor- 
tunately is not very fresh, is given in Table II (analysis 
15). The pseudo- diorite zone is very irregular; in 


places where the granite appears to be in contact with 


the schist it does not even seem to be present sometimes ; 
at other times it may be two or three hundred feet wide. 


With it are associated narrow epidotic stringers that 


extend beyond the pseudo-diorite zone often for some dis- 
tance, it may be for tens or hundreds of feet, into the 


adjacent schist. 


463 


Hawkins—N otes on the Geology of Rhode Island. 


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464 Hawkins—Notes on the Geology of Rhode Island. 


Five analyses of rocks from Neutaconkanut Hill are 
given in Table Lil (analyses 18, 16, 17, 18, 19) and three 
from Berkeley (analyses 14, 21, 22). Analysis 13 
was made upon material taken at a point about 100 feet 
from the granite, and represents an apparently little 
altered green schist, while the rock of analysis 16 has a 
typically coarse speckled appearance, giving it a dioritic 
aspect; it was taken from within 25 feet of the contact. 
The ‘‘xenolith’’ of schist was found as a well-defined 
dark-colored inclusion in the granite, which lies close 
together with several other xenoliths in the ledge at a 
point nearly 50 feet from the nearest green schist out- 
crop. The granite of analysis 18 is mapped as Milford 
granite by Emerson and Perry, on the southeast flank of 
the hill. It is abnormally dark-colored and is filled with 
closely spaced chunky phenocrysts of secondary feldspar. 
It is about 20 feet from the green schist contact. The 
nearest granite that is free from inclusions and abnormal 
dark color, with which the above intrusive can be com- 
pared, is at Hughesdale, a mile and a half west (analysis 
19). This latter type is fully 1000 feet from the nearest 
included rock, which is a quartzite, and seems to be a type 
of the Milford granite gneiss free from any large amount 
of foreign substances. 


The exposures at Berkeley are not so satisfactory in | 


character, but the same phenomena are strongly devel- 
oped. The rock represented by analysis 14 is at least 
200 feet from the granite; that of analysis 21, the pseudo- 


diorite, is about 100 feet from it. The granite is dark 


and porphyritic, but zenoliths suitable for analysis were 
not found. There is also no granite in the vicinity free 
from schist. 

Comparison of the analyses shows what appears to be a 
unity of action in the exchange of elements by pneumat- 
olysis during this contact metamorphism. Alumina 


becomes segregated somewhere near the contact, as does » 


also soda and to some extent potash (although appar- 
ently not enough to form much biotite, as has been gen- 
erally supposed). Ferric iron is very largely reduced 
to the ferrous state and magnetite appears, both in the 
eranite and in the invaded rocks (especially noticeable in 
the case of the wall rocks surrounding some Rhode Island 
pegmatites). It is interesting to note that W. G. Foye, 
in a recent publication concerning the contact action of 


Hawkins—N otes on the Geology of Rhode Island. +465 


the nepheline syenites and related rocks in Ontario, Can- 
ada, finds in general the same transfers taking place.** 

It was probably on account of the abundance of avail- 
able silica in the solutions accompanying the Rhode 
Island granites that no rare rocks were formed. It will 
be noticed, however, that of all the materials exchanged 
in this process of contact metamorphism, the lme is 
apparently the most easily displaced. Some of this hme 
the granite has assimilated, as is shown by its abnormally 
high content of CaO. A considerable portion of the lime, 
however, which is not found in the original rocks on 
either side of the contact, has been expelled, reappearing 
as calcite veins, shown near the granite contact on the 
east slope of Neutaconkanut Hill and in similar relations 
on the west slope (compare Emerson and Perry, op. cit., 
25). A reasonable enlargement or extension of this 
action leads us to a consideration of Professor Brown’s 
further suggestion, that the hmestone deposits of Lime- 
rock and elsewhere in that part of Rhode Island might be 
entirely the product of contact metamorphism resulting 
from invasion of the green schist by granite batholiths 
at considerable depth. 

The limestones of the State, belonging to what Emer- 
son and Perry have called the Smithfield hmestone mem- 
ber of the Marlboro Formation (op. cit., 16 et seq.), are 
erystalliine marbles appearing as lens-shaped bodies, 
usually in the green schist, often near its contact with 
the granite, though at times wholly surrounded by the 
granite itself. The total volume of limestone repre- 
sented is probably somewhat more than a million cubic 
yards. Much of it is a very pure limestone; parts of it 
are more or less magnesian, and the marginal portions, 
for thicknesses at times as great as ten feet next to the 
schist walls, are often dolomite. This latter fact might 
be attributed to segregation in metamorphism, although 
it may of course have been an original feature. Irregu- 
lar zones are filled with pure white bladed and fibrous 
tremolite (shown to be such in the thin section), which in 
one sample of limestone from the Dexter quarry was 
found to constitute 80-54% of the rock, the remaining 
19-46% being all that was soluble in boiling hydrochloric 
acid. According to Van Hise** such silicification in 

® Foye, W. G., this Journal, 40, 413-436, 1915. 

** Van Hise, C. R., U. S. Geol. Surv., Mon. 47, 971, 1904. 


Am. Jour. Sct.—Fourts Series, VoL. XLVI, No. 272.—Aveusrt, 1918. 
17 


466 Hawkins—Notes on the Geology of Rhode Island. 


limestone goes on as a natural result of burial in the zone 
of anamorphism, and is not dependent upon introduction 
of siliceous emanations from invading granites. Tale 
and serpentine (bowenite), occurring locally in the lime- 
stone, must have been derived from hydration of the 
silicates by circulating waters; the bowenite may possi- 
bly represent included layers or fragments of material 
from the adjacent schist. Analyses of the limestone 
have been published (Emerson and Perry, op. cit., 17-18). 
The additional analyses which follow (Table IIT) may 
serve to show the relations of the granites, pseudo- 
diorites, and green schists, where they are found 
together. The details appear to be somewhat as 
follows :— 

The granite from the east slope of Neutaconkanut Hill 
is found to show the following gains when Eu eo with 
the normal Milford granite at Hughesdale :— 


UN One cee Poe a ae 4-09 % 
Hes ives aes 1:90 
RE Ow Sak enh Tee 72 
Who O cee vi ean it 
Ca Oats enoo bsnl a panes 4-10 
11-38% 


This sum indicates that, if the increase in basicity be due, 
as it apparently is, to assimilation of the basic rock, 
11-38% of the granite at a distance of 20 feet from the 
contact is assimilated schist. If this be true at 20 feet 
from the contact, it is reasonable to suppose the same 
conditions to continue the same on the average from the 
contact to a point at a distance of 25 feet from it. Then 
in this 25-foot band of granite there is 11-38% of schist 
intermixed, i. e., 11:38% of the amounts of elements 
oained by the granite, present in the schist analysis, is 
present in every like amount of the granite, to a distance 
of 25 feet; or the full amounts of elements present in the 
schist analysis are present in every 11:38% of 25 feet, or 
2-84 feet, of the granite; this represents the amount of 
schist (2-84 feet) that has been assimilated. For the 
Neutaconkanut Hill locality this much at least is indi- 
cated by analysis, although possibly more schist was 
assimilated in portions of the granite nearer to, and less 
in those farther away from, the contact. These zones are 
not shown on account of lack of exposures. To distances 


Hawkins—N otes on the Geology of Rhode Island. 467 


of 25 feet and more from the contact, small schist xeno- 
hths 2 by 4 or 5 em. are not uncommon in the granite, 
which is dark colored, porphyritic, and surrounded by 
and intermixed with schist. 

The amount of CaO in the green schist of Neutaconka- 
nut Hill is 8-99%. Of this the granite has been able 
to assimilate 4:10%. The small fragmentary xenoliths 
of schist remaining in the granite retain 1:37%. The 
residue which goes to form calcite deposits is thus about 
38-02% of CaO, or an amount equivalent to 3:52% of the 
original schist. As CaCO, this would be 6:28%. 

If 2-84 feet of schist be assimilated, in any portion of 
the contact zone 2-84 feet wide, 10 feet deep and one mile 
long, containing 5,554 cubic yards, or, in other words, 
along a mile of contact line where the contact is 10 feet 
deep and the granite is affected as the analysis indicates 
for at least 25 feet from the contact :— 


CaO liberated as calcite — 195-5 cu. yd. 
CaCO, produced as calcite = 349-06 cu. yd. 
For similar contact 
100 ft. deep CaCO; produced as calcite = 3,490-6 cu. yd. 
10,000 ft. deep CaCO; produced as calcite = 349,060. cu. yd. 


Contact lines are in all probability fully as deep as the 
last figure noted. <A careful and conservative estimate 
of the actual volume of the limestone present in field 
exposures is as follows :— 


Harris Quarries, total volume = 465,275 cu. yd. 
Dexter Quarry, total volume = 333,333 cu. yd. 


The Harris deposit consists of three limestone lenses, 
probably disconnected and perhaps overlapping; the 
total length between north and south extremities of this 
series 1s about 1000 feet. The Dexter limestone is a 
single lens located 2 miles east of the Harris quarries. 
Its length does not much exceed 500 feet. 

Comparison of the above figures, especially those from 
the Harris quarries, with the theoretical results obtained 
from the analysis, seem to indicate that, given a suff- 
ciently deep line of contact between granite and green 
schist, such limestone deposits as those here found might 
have originated from contact action alone. The writer, 
however, for reasons stated below, does not believe that 
they actually are the result of such a process. 


468 Hawkins—Notes on the Geology of Rhode Island. 


A summary of the behavior of the CaO in the contact 
zone between the granite and the green schist at Neuta- 
conkanut Hill appears to be as follows :— 

The amounts of CaO present in the various types 


analyzed are :— ‘ 
In In In In In 
Green Schist. Pseudo-Diorite. Xenolith. Modified Gr. Unchanged Granite. 
Ca0 =8:99% 800% “1.37% 41% AT%, 


Comparison of the above amounts of CaO with the 
amount of CaO originally present in the schist indicates 
its distribution as follows :— 


( 1:37% 
CaO left in xenoliths: 
8-99% (15-24% ) ( 352% 
CaO originally present: { CaO forming calcite: 
(100-%) 762% | (39-15%) 
| CaO lost thr. metamorphism: 4 
[ (84-76%) 410% 
| CaO assimilated by granite: 
t (45-61%) 


If the limestones be metamorphic in origin, a source 
must be found for the CO, required in the formation of so 
much carbonate. The CO, must then probably be 
regarded as derived from emanations from the intrusive. 
That such discharge of CO, does take place is recorded 
by Van Hise.*° The fact that under such conditions eal- 
cium silicates were not formed must then be regarded as 
the result of the inferior strength of silicic acid com- 
pared with that of carbonic acid under conditions of not 
very deep burial, where temperatures and piesa were 
not high (op. cit. i Noeoy) 

Closely associated with the limestone ee are often 
interesting deposits of steatite, with associated hydrated 
and carbonated minerals. These soapstones are com- 
monly gray in color with obscure fibrous structure, and 
occasionally carry veins of green foliated tale of a supe- 
rior degree of purity (as at Manton and at Manville). 
On the borders of the steatite areas, which are at times 
50 feet or more wide, there are gradations into green 
schist, suggesting a derivation of the soapstone from the 
schist, supposedly by a weathering process (Van Hise, 
op. cit., 24), although the possible action of heated waters 

3 Van Hise, C. R., op. cit., 960-970. 


Hawkins—N otes on the Geology of Rhode Island. 469 


connected with granitic intrusions might have caused the 
formation of the original silicate minerals from which the 
steatite must have been formed. In the writer’s opinion 
the steatite, and the lhmestones associated with it, at least 
the smaller limestone masses, are the product of subse- 
quent alteration of earler silicates of magnesia and lime 
which were formed in connection with the intrusion of the 
granite, replacing portions of:the schist. An analysis of 
the fine-grained gray steatite of this type is hereby given 
(Table III, analysis 20). This rock is closely associated 
with a coarser phase which has a groundmass principally 
composed of fibrous tale and steatite with a little calcite, 
in which are embedded black, lustrous ankerite crystals, 
©) mm. in diameter, with bright cleavage. This latter 
phase shows the mineral composition to be expected in 
the finer grained mass analyzed. A recast from the 
analysis to form these minerals gives the following 
results :— 


Recast of Chemical Analysis of Steatite from Manton, f. f[. 
(Analysis 20.) 


Pee Cdicite:.- = 410% 
eS  [Siderite — 3-37 
Magnetite = 4-73 
Pyrite =a AOD 
12-22% 
( SiO, == 9:39 Yo | 
eee Oa te 74504\7.4 
| FeO = A495] 
Soapstone) NEV, - eee An aggregate of green schist, 
Matrix | K,O zu eee partly changed to tale. 
ettO aati Ee ae 
| 
[ 88-17% | 
Total : - 100-39 % 


Of the soapstone matrix (88-17%), the amount of water 
present therein (1:23%, compared with 480% in tale), 
indicates that tale forms 25-64%. 

The soapstone analysis (20) when compared with that 
of the unaltered schist (analysis 12), shows changes 


470 Hawkins—Notes on the Geology of Rhode Island. 


which have taken place in the schist as follows, curiae 
alteration to soapstone :— 


Almost complete loss of Al,O,. 

Some loss of Iron. 

Relatively enormous gain in MgO. 

Large loss of CaO, and also of Na,O and K, O. 


Oxides thus lost to the schist are segregated in tale veins 
or elsewhere in the vicinity, as shown in the ease of the 
narrow, irregular veins replacing green schist along 
joint planes in the Manton Avenue quarry, adjacent to © 
the steatite deposits, containing the following minerals, 
in their order of crystallization :— 


Pink orthoclase; short chunky crystals 1 or 2 mm. in 
diameter, shown by petrographic examination to be Carlsbad 
twins. Sheaf-like rosettes and typical crystals in cavities. 

EKpidote; fine granular crystalline mass, forming slender 
acicular erystals in cavities. 

Calcite, filling all remaining openings. 


The presence of epidote and of orthoclase argues in favor 
of deposition by hot waters probably emanating from an 
intrusive granite. 

Another contact deposit is to be seen just west of South 
Foster (Hopkins’ Mills), where the new State road 
passes the white school-house near the top of the hill. 
Here there is rather poorly exposed at least 50 feet of a 
marbled gneiss composed of biotitic gabbroid material 
thoroughly intruded in lit-par-lit fashion by granite,*® 
and 25 feet from this, a 25-foot outcrop of a fine-grained, 
rather impure looking limestone marble (shown upon 
treatment with hydrochloric acid to contain about one- 
fourth of its volume of silicates, resembling tremolite and 
scapolite). Between the basic gneiss and the marble 
there lies a vein deposit which appears to have been 
formed as a result of the invasion of siliceous emanations 
from a granitic intrusion, reacting with the gabbro or 
limestone, or both. Pneumatolytic action of this sort is 
shown by the presence of apatite. The irregular vein 
deposit shows minerals developed as follows: | 


Wernerite; light gray, well formed individuals, some as large 
as 3 em. in diameter and 5 to 10 em. long, tapering at the ends, 
without definite terminations; within, they are fine grained 


*° Compare Emerson (idem, Pl. V, Fig. A, and Pl. IX, Figs. A and B). 


Hawkins—N otes on the Geology of Rhode Island. 471 


eranular in appearance, containing a small quantity of inter- . 
mixed biotite particles. These crystals are embedded in biotite. 


Then follow several minerals intergrown, as follows :— 


Actinolite; a felt of light green blades. 

Biotite; large finely crystalline masses, free crystals in 
cavities. 

Epidote; compact, feldspathic, with occasional grains of 
quartz. 

Apatite; tiny, brilliant white crystals, on the biotite in cav- 
ities. The crystallographic forms were determined as follows 
by use of the two-circle goniometer:—o, (0001); s, (1121); 
peeeed = a. (1011): 7 (1012): 2: (3031). .a, 010). ~ Also-a 
pair of faces belonging probably to a first order pyramid near 
(6-6-12-1), a form whose presence could not be fully established 
because of lack of material, but which is new to the species. 
(Letters given are those of Goldschmidt. ) 


That the limestone beds of Rhode Island were sedi- 
mentary in origin was the conclusion of Kmerson and 
Perry (op. cit., 16), and is also the opinion favored as 
the result of the present studies. In metamorphism all 
traces of original bedding or of possible fossil remains 
have apparently been destroyed, and other misleading 
features, such as bands of color, have been introduced 
by the same agency. There are restricted areas of mar- 
ble, however, in the Dexter quarry especially, which 
possess a very marked gray color, and seem to represent 
brecciation products of certain zones in which the dark 
material was earlier segregated. In the laboratory this 
’ limestone was treated with hydrochloric acid, the insolu- 
ble residue being gray. When this was brought to red 
heat in a erucible the color quickly changed to a light 
vellow, indicating the source of the dark color to be 
earbon. This amounts locally to about half of one per 
cent of the rock. It is also shown by the application of 
further chemical tests to be in the form of finely divided 
eraphite. Carbon of this kind when present in limestone 
is usually thought to have had its origin in organic 
remains and to indicate the sedimentary nature of the 
hmestone. A study of the geology in Porto Rico has 
shown?’ that the occurrence of lime beds 1n a sedimentary 
series of voleanic tuffs (such as the green schists may 
once have been) is very common in that country. 

* Berkey, C. P., Annals N. Y. Acad. Sci., 26, 1-70, 1915. 


472 Hawkins—Notes on the Geology of Rhode Island. 


Along the western side of the southern Harris lme- 
stone quarry there is exposed a block of fine-grained 
granite containing sharply defined inclusions of green 
schist and of crystalline limestone, within a few inches of 
each other. Neither of the included fragments seems 
different from the adjacent large exposures of similar 
rocks. The granite surrounding them may be an aplitic 
phase, and later in age than the main granitic intrusion, 
but its presence certainly suggests that the limestone as 
well as the green schist may be pre-granite in age. 

Throughout the western and northwestern portions of 
the State, where granites greatly modified by assimila- 
tion of basic rocks are repeatedly found in contact with 
the latter, only one small limestone deposit was found, 
the rather insignificant one at South Foster mentioned 
above. Apparently the granite was ableto assimilate all 
of the lime which it derived from the partial assimilation 
of the gabbros throughout this area, possibly because of 
more deep-seated intrusion than in the area farther east. 

Whether sedimentary or metamorphic in origin, the 
limestone of Rhode Island has without doubt been second- 
avily segregated by solution during metamorphism, 
contact or regional. If it be attributed to contact action, 
the solutions may have been rising to points above, 
toward the top of the batholithic dome. The present 
attitude of the beds at least is highly inclined. Subse- 
quent shearing has also helped in the formation of the 
present lens-shaped bodies (Kmerson and Perry, op. 
cits, 16)). 

The sincere thanks of the author are due to Professor 
C. W. Brown of Brown University for his many helpful 
suggestions and guidance during the course of this inves- 
tigation; to Professor Charles Palache of Harvard Unt- 
versity for aid in the crystallographic study of the 
minerals here described, and to all others who in various 
ways have contributed something to the work. 


Houston, Texas. 
December, 1917. 


Phillips—V anadium wm Sedimentary Rocks. 478 


Arr. XVIL.—4 Possible Source of Vanadium im Sedimen- 
tary Rocks; by ALExanpER H. PHILLtps. 


Included in the materials collected at the Tortugas and 
analyzed for metals (some of the results of which were 
reported and published in the annual report of the Car- 
negie Institute for 1917), was a brown spotted holothurian, 
Sticopus mobu, which was analyzed by the methods there 
indicated. When the ash from this material was dis- 
solved in hydrochloric acid, a deep blue solution was 
obtained, resembling in depth of color that of a saturated 
solution of copper sulphate, but to my great surprise this 
color was not due to copper but to vanadium. The 
material when collected was cleaned of all sand externally 
and the sand content of the intestines was also removed. 
It was then dried at 110°C. 

The amount of each constituent determined in a 
20 gram sample of this dried material is here expressed 
in grams. 

Copper Tron MnO Vanadium 
‘0009 ‘0178 ‘00022 ‘0247 

The amount of the element vanadium in this material 
is 0-128 per cent of the weight of the entire animal dried 
aie)? C. | 

Vanadium, I believe, has never been reported from sea- 
water; however, this holothurian must have collected its 
vanadium either directly from the seawater or from its 
food which in turn must have concentrated it from the 
seawater. 

The Tortugas are far enough removed from the con- 
tinental shore or the mouth of any river, not to be 
influenced by the sediments carried into the gulf. Their 
formation is practically entirely that of carbonates of 
calcium and magnesium, both of which are either of 
organic or precipitated origin. 

Occurrence of Vanadiwn.—Vanadium occurs dis- 
seminated in small quantities in almost all igneous rocks. 
There are, however, few localities in igneous rocks where 
it has been concentrated in sufficient quantities to pay 
commercially for the labor of mining. The source of 
commercial vanadium is practically that of the sedimen- 
tary rocks or coals. 

Vanadium has been reported in a fresh water from 
Brookline by A. A. Hays, and in the blood of an acidian 


474 Phillips—Vanadwm wm Sedimentary Rocks. 


from the Bay of Naples by M. Henze,! to the amount of 
18-5 per cent of VO; of the chromogen. This vanadium | 
content of the blood does not seem to be a characteristic 
of all acidians, as two species from the Tortugas yielded 
no vanadium, neither did two other species of holothu- 
rians yield vanadium. 

These two species in which vanadium has been found 
in considerable quantities are widely separated in the 
scale of animal life, one being a Chordata and the other is 
an HKchinoderm, indicating the possibility of other forms 
which may use vanadium as an oxygen carrier in their 
vascular system. 

The source of vanadium in sedimentary rocks and coals 
has always been somewhat of a puzzle, and while we have 
no way of determining the density of holothurian life in 
the past or whether the use of vanadium physiologically 
was developed paleontologically early or late, holothu- 
rians very similar to the recent species are present in the 
Jurassic of Europe, and according to Walcott they 
existed in the middle Cambrian shales of British 
Columbia. 

It does not seem impossible that such forms as 
Stickopus mobw concentrating vanadium to the amount 
of 0-12 per cent by weight of their dried tissues, living in 
shallow waters in large numbers, where sediments were 
collecting or limestones were forming, that this vanadium 
content of their tissues, at death, could easily be fixed and 
held as a constituent of the sedimentary rocks thus 
formed. 

The fixation of vanadium in the sediments of the Tor- 
tugas would be a simple matter, as there is an excess of 
calcium carbonate always present and in the presence of 
which, vanadium salts are practically insoluble.2 Vana- 
dium also forms many salts with calcium, some of which 
are soluble in water and others are difficultly soluble, but 
all are practically insoluble in slightly alkaline waters, 
such as seawater, and in the presence of calcium car- 
bonate. 

A second possibility of the fixation of vanadium under 
the above conditions is the presence of hydrogen sulphide, 
which is constantly liberated in the slimes of the man- 
grove lagoons and shallows. This in a slightly alkaline 


17. Phys. Chem., 79, 223. 
2 Notestein, F. B., Econ. Geology, 13, 50. Origin of Uranium and Vana- 
dium ores. 


Phillips—Vanadium in Sedimentary Rocks. 475 


solution would precipate vanadium as the sulphide, to be 
covered up and preserved as a small vanadium content, 
in this case, of a future limestone. 

Vanadium also forms double salts with copper and 
calcium, as in case of the minerals volborthite (CuCa).- 
(OH),.VO,6H,O and cealciovolborthite (CuCa),(OH)- 
VO,. It would seem that both of these minerals would be 
possible under the conditions described, as the ash of this 
holothurian also contains 0-0045 per cent of copper, and 
it has been shown that many forms contain both copper 
and zine which also enters into the composition of vana- 
dium minerals. 

With small amounts of vanadium disseminated in cer- 
tain sedimentary rocks and limestones, it is not difficult 
to explain its secondary concentration in the fissures, 
faults or joints of these same or nearby rocks. 


Geological Department, 
Princeton University, May 18th, 1918. 


ScrHENMPIFTC INTELLIGENCE, 


I. Grotogy anp MINERALOGY. 


1. Fossil Plants: <A text-book for students of Botany and 
Geology; by A. C. S—ewarp. Vol. III, small 8vo, pp. xviii, 656, 
with 253 text-figures, and frontispiece portrait of Zeiller. Cam- 
bridge, 1917 (The University Press).—A notice of the first vol- 
ume of this work (1898) was given by G. L. Goodale in this 
Journal in June, 1898 (5, 472); and of the second by the writer 
in November, 1910 (80, 356). Continuing from the Pterido- 
sperms not directly recognized as seed-bearing, with which vol. 
II closes, the main topics of the present volume are: Pterido- 
spermex, Cycadofilicales, Cordaitales, Cycadophyta. The intro- 
ductory pages are occupied by an interesting account of the 
existing cycads; the critical discussion of mesarch bundles 
(p. 32) being noteworthy. The bibliography appended is not 
impeccable; both the monographs of Fontaine on the Mesozoic 
Floras are unnoted, and this omission of fine American material 
represents a serious gap in Professor Seward’s general dis- 
cussion. 

There are many special features in the assemblage of indis- 
pensable data for both reader and student. In some eases there 
is a tendency to arbitrary treatment, always most difficult to 
avoid during condensation of extensive work in the light of new 
facts. Generally the points are well taken. Lyginodendron 
becomes Lygtnopteris, and Bennettites is relegated to the syn- 


476 | Scientific Intelligence. 


onomy; though one may doubt whether paleobotanists will 
willingly give up Yuccites, long used for striking forms of the 
lias and other Mesozoic formations. 

Always a zealous reader, Professor Seward enlivens his pages 
with many apt references, and there is a real charm to the quo- 
tations of well-put opinion, rescued from the ever increasing mass 
of contributions. For instanee, it was Williamson (p. 305), who 
suspected from the great variety of ancient seeds that ‘‘there 
were in the Carboniferous forests many gymnospermous stems 
clothed with foliage of which we have not yet discovered any 
traces, probably because these Gymnosperms did not flourish 
upon the low swampy grounds which were the homes of the 
great mass of the coal producing plants.’’ Even the detection of 
the seed ferns fails to rob this view of all its force. 

The account of the Williamsonians brings into full view this 
remarkable Mesozoic tribe. Walliamsoniella with its small cune- 
ate stamens confirms and extends previous observations. But 
the interpretation of what Lignier felicitously termed the 
‘“litigious’’? Williamsonian disk and cone easts, is far from con- 
vineing. These are held to indicate a terminal [apical] whorl 
of conecrescent microsporophylls surmounting the ovulate cone 
(fig. 547). Nevertheless, in the reviewer’s judgment it is still 
probable that these flowers, though capable of great variation, as 
well as dioecism, all adhered to, or varied directly from, the 
essentially magnoliaceous plan, with the stamens hypogynous. 

It is stated (page 126) that precise information as to the 
structure of Codonotheca is not yet available; but this ought 
rather to be said of the various comparable European types, 
some of which are probably misealled seeds. Also, Codonotheca 
suggests the disk hypothesis of Wieland just as distinctly as the 
synangial theory of Benson, for the origin of the ancient leafy 
seeds. 

No one will find the round number of text figures large, and 
full half as many more would have been welcome. Some of the 
halftones are, however, vague, and the ‘‘fruit cavity’’ in the 
historic Dresden Cycadeoidea (fig. 534) looks mysterious. 

While giving momentary attention to some of these mooted 
points, in whieh it must be confessed paleobotany still abounds, 
it is mainly wished to accentuate the importance of Professor 
Seward’s work. His volumes must long remain a standard. 
Indeed they constitute a great milestone in the effort to reach 
precision in the study of ancient plants, and it is hoped the con- 
eluding volume (or volumes) may soon appear. G. R. W. 

2. The Cedar Mountain Trap Ridge near Hartford; by W. M. 
Davis (communicated).—The writer desires to put on record 
an observation made during a recent visit to Hartford, concern- 
ing the trap ridge known as Cedar Mountain that extends south- 
ward from near that city. The ridge was interpreted by Prof. 
Wm. North Rice of Middletown, who was associated with me 25 


Geology and Mineralogy. 477 


years ago in reporting on the Triassic formation of the Con- 
necticut valley for the U. S. Geological Survey, as a part of the 
so-called ‘‘main sheet’’ of trap, locally uplifted on a north-south 
fault; although the normal sequence of overlying sandstones with 
the thin posterior trap sheet was found to the east of the ridge, 
the underlying sandstones were not then visible at the west base 
of the ridge. In their absence the thickness of the ridge-making 
trap sheet could not be determined and its identity with the 
heavy main sheet in other ridges to the south and west remained 
to that extent uncertain. 

In later years a large quarry, conspicuously visible from the 
main railroad line near Newington station about a mile away, 
has been opened in the west face of Cedar mountain; the trap is 
thus laid bare for about a quarter-mile north and south in three 
ereat excavations. The northern quarry has its floor about 20 
feet above the drift-covered low land to the west; no underlying 
sandstone is there exposed. The middle quarry is cut down to 
the lowland level, and the underlying red sandstone, dipping 
eastward about 20 degrees, is well exposed in its southwestern 
part to a thickness of 10 or 15 feet; at the contact of sandstone 
and trap, the trap is dense and much finer grained than in the 
greater part of the quarry face; and the sandstone is indurated 
and jaspery for a foot or two below; the bedding is hardly dis- 
turbed. The southern quarry has its floor about 50 feet above 
the lowland; here the sandstone is laid bare, with a steep glaci- 
ated face, between two rock-crusher buildings; also at the south- 
ern entrance to the quarry, but no contact with the trap is visible. 

The thickness of the trap sheet is thus limited underneath at 
a measure that is closely comparable with the thickness found 
elsewhere. On crossing the trap ridge to the east, a ravine fol- 
lowed by a road was seen to enter it obliquely from the north, 
probably a consequence of a branch fault; farther down on the 
eastern slope, no sandstone could be discovered in contact with 
the upper surface of the trap sheet; but the stone walls con- 
tained a-good number of blocks composed of grayish sandstone 
containing fragments of vesicular trap, such as characterizes the 
sandstone at overlying contacts on the back slope of the main 
sheet in other ridges, which are thereby proved to be extrusive 
lava flows. The identification of Cedar mountain as an 
upfaulted part of the main trap sheet is thus supported. 

3. Canada, Department of Mines—The following list con- 
tains the titles of recent publications of the Canadian Depart- 
ment of Mines. (See vol. 44, pp. 81-83.) 

(1.) Geological Survey Branch; Wiui1AM McINNEs, Direct- 
ing Geologist. 

Memorrs.—No. 84. An exploration of the Tazin and Taltson 
rivers, North West_Territories; by CHARLES CAMSELL. Pp. 124, 
1 map, 18 pls. 

No. 87. Geology of a portion of the Flathead Coal area, 


478 Scientific Intelligence. 


British Columbia; by J. D. MAcKeNzim: Pp. 53, 2 maps, 1 
plate, 1 fig. 

No. 95.> Onaping’ Map-Area; (by W. i. Comune: 4Ep ae 
2 maps, 11 pls. 

No. 98. Magnesite deposits of Grenville district, Argenteuil 
county, Quebec; by M. E. Witson. Pp. 88, 3 maps, 11 pls:, 
2 figs. 

No. 99. Road material surveys in. 1915; by Li. REINECKE. 
Pp. 190, 2 maps, 10 pls., 10 figs. 

No. 100. The Cretaceous Theropodus Dinosaur Gorgosaurus ; 
by Lawrence M. Lampe. Pp. 84, 49 figs. This is a carnivorous 
Dinosaur from the Belly river formation of Red Deer river, 
Alberta, first described by the author in April, 1914 (Ottawa 
Naturalist, vol. 28). It had an estimated length of some 28 or 
29 feet and the restoration of the type specimen is well shown on 
a separate plate (x 1/18), fig. 49. 

No. 101. Pleistocene and recent deposits in the vicinity of 
Ottawa, with a description of the soils; by W. A. JOHNSTON. 
Pp. 69, 1 map (scale 1 mile to 1 inch, to be had separately), 8 pls. 
No. 102. Espanola district, Ontario; by TERRENCE T. QUIRKE. 
Pp. 92, 1 map, 6 pls., 8 figs: 

No. 103. Timiskaming County, Quebec; by M. E. Wiison. 
Pp. 197,11 map; 16-pls., 6 figs: 

Museum Buuuetin.—No. 27. Contributions to'the Mineralogy 
of Black Lake area, Quebec; by EUGENE PoirTEvIN and R. P. D. 
GRAHAM. Pp. 82, 12 pls., 22 figs. See the following notice. 

SuMMARY Report for 1916. Pp. 419, 138 maps, 12 figs. 

(2.) Mines Branch; EuGENE HAANEL, Director. 

No. 217. Iron Ore Occurrences in Canada. In two volumes, 
compiled by E. LinpemMAN and L. L. Bowron. Introductory by 
A. H. A. Ropinson, with appendixes containing numerous maps 
in separate covers. 

BuLuetTINS.—No. 14. The Coal Fields and Coal. Industry of 
Eastern Canada; a general survey and description; by FRANCIS 
WieGRAy. Ep. Gi lamep. 26 pls ol te 

No. 15. The Mining of thin coal seams as applied to the 
Eastern Coal Fields of Canada; by J. F. KELLocK Brown. 
Pps lemap, i plate, Oi mes: 

No. 17. The value of peat fuel for the generation of steam; 
by JoHN Buizarp. Pp. 42, 1 plate, 5 figs. 

No. 19. Test of some Canadian sandstones to determine their 
suitability as pulpstones; by L. HeBer Cour. Pp. 6, 6 pls., 
4 fies. 

SumMMARY Report for 1916. Pp. 183, 14 pls., 10 figs. 

Also separate reports on the production for 1916 of copper, 
gold, lead, nickel, silver, ete.; of iron and steel; of coal and coke. 

Further, the Preliminary Report on the Mineral Production of 
Canada for 1917 (JoHn McLeisu, Chief of Division of Mineral 
Resources and Statistics). The total valuation of all products 


Miscellaneous Intelligence. 479 


is estimated at very nearly 200 million dollars. This is an 
inerease of about 9 p. c. over 1917, and 40 p. c. over 1916. 

4. Contributions to the Mineralogy of Black Lake Area, 
Quebec; by KuGENE Potrevin and R. P. D. Granam. Mus. Bull. 
No. 27, Dept. Mines, Can. Geol. Surv., 1918, pp. 82, pls. 12, figs. 
22.—An important asbestos and chromic iron district is located 
in the southeastern part of Ireland and the northwestern part 
of Coleraine townships, Megantic county, province of Quebec. 
Unusual minerals have been obtained from the various mines and 
pits of this district for a considerable time but no systematic 
study of them has previously been published. After a short 
introduction giving the general geological features of the area 
and a section devoted to a consideration of the genesis of the 
minerals, the authors give a detailed description of the different 
species observed. Some thirty-four different minerals are noted, 
chemical analyses and the results of crystallographic and optical 
study being given for the most important. The following miner- 
als are especially interesting; Stichtite, previously known only 
from Tasmania, has been identified here. Diopside is found in 
minute erystals of unusual habit, their color being either color- 
less, lilac or yellow; some eleven new forms have been identified 
on the erystals together with a large number of rare forms; 
analyses show that the material is almost of the normal type rep- 
resented by the formula CaMg(Si0,),. Both grossularite and 
andradite garnets are found; the crystals are notable frequently 
having rare tetrahexahedral and hexoctahedral forms, one 
type showing the hexoctahedron (853) almost in simple develop- 
ment. Small and exceptionally brilliant crystals of vesuvianite 
also occur, showing the following colors: colorless, lilac, emerald- 
green, pale yellow and reddish brown. A new mineral colerain- 
ite was also found. An abstract of its description has been 
given in this Journal, see 45, 478, 1918. W. E. F. 


II. Muiscetnanrous Screntiric INTELLIGENCE. 


1. Field Museum of Natural History—Annual Report of 
FREDERICK J. V. SkirF, Director, to the Board of Trustees for the 
year 1917. Pp. 147-222, with numerous illustrations. Notwith- 
standing ,adverse conditions gratifying progress on the new 
museum building in Grant Park is noted. It is stated that the 
steel for the roof of the entire building (except entrances) would 
probably be in place by April, 1918. 

Botanical Series. Vol. 4, No. 1. New Species of Xanthium 
and Solidago; by CHARLES FREDERICK MimuspaueH and Earn E. 
SHERFF. Pp. 7, 6 pls. 

2. The Sarawak Museum Journal; issued by the Sarawak 
Museum under the authority of His Highness the Rajah—Part 
IIT of vol. 2, pp. 287-424 contains an important memoir, entitled 
‘Keys to the Ferns of Borneo;’’ this is by BE. B. CopEuann, 
professor of plant biology, University of the Philippines. 


480 Scientific Intelligence. 


3. The Normal and Pathological Histology of the Mouth; 
by ArtHur Hopewett-Smiru. Vol. I, Normal Histology. Pp. 
xvii, 345, with 2 colored plates and 262 text figures. Philadel- 
phia, 1918 (P. Blakiston’s Son and Co.).—This is the first of the 
two volumes of a second, revised and enlarged edition of the 
author’s ‘‘ Histology and Patho-histology of the teeth and asso- 
ciated parts.’’ It describes the cellular formation and _ histo- 
genesis of all the organs of the mouth, but has partieular 
reference to the structure and development of the teeth. The 
subject is treated comprehensively, the dental structures found in 
various mammals, reptiles and fishes being introduced for com- 
parison. Debated questions concerning the functions of various 
types of cells are discussed in an appendix. Both text and illus- 
trations require the highest commendation. WwW. R. C. 

4. Helvetica Chimica Acta (Georg & Co., Basel, Geneva ).— 
The Swiss Chemical Society, founded some seventeen years ago, 
has recently issued the first part (pp. 1-96) of a new periodical, 
under the title given above; it is to be devoted to pure chemistry 
and to serve as the organ of the Society. The editorial commit- 
tee consists of MM. Bosshard, Fichter, Guye, Pictet, Rupe and 
Werner, all of Switzerland. The present plan is to issue 6 to 8 
parts yearly, aggregating from 500 to 1000 pages; the subserip- 
tion price is 25 franes per year. This undertaking is particu- 
larly noteworthy in view of the difficult situation economically 
occupied by Switzerland at the present time, and the disinter- 
ested contributions which the country is so freely making in 
behalf of suffering humanity. 


OBITUARY. 


WiuuiAmM Earu Hippen, well known for his work in American 
Mineralogy, died at his country home, Ocean Grove, N. J., on 
June 12, 1918, at the age of sixty-five years. He was early 
engaged as an artist, but his interest in minerals led to his spend- 
ing many years in the search for rare specimens, particularly 
those of commercial value found in the South. One of the 
remarkable localities investigated by him was that in Alexander 
County, N. C.; from it came the emerald-green variety of 
spodumene, used as a gem and which received the name Hid- 
denite (1881). He also developed the deposit of rare minerals 
at Burnett, Llano Co., Texas. The pages of this Journal contain 
many notes and articles on minerals by him particularly from 
1880 to 1905. 

Sir ALEXANDER PEDLER, F.R.S., died on May 13 at the age of 
sixty-eight years. He was early an active investigator in chem- 
istry and in 1873 was made professor of chemistry at Calcutta; 
later he was prominent in the meteorological service and in other 
official lines; since 1907 he had been honorary secretary o the 
British Science Guild. 


as 


VA fe 
Ys 3 1916 


ING 8 PATENT | oe” 
AU Jeb 13) ee 


AMERICAN JOURNAL OF SCIENCE 


PROUUR TH SERIES. | 


Art. XVII—A Modification of the Periodic Table; by 
Inco W. D. Hackn. 


About fifty years ago Newland! recognized a certain 
periodicity among the elements and compiled his well 
known ‘‘octaves.’’ At that time chemical knowledge had 
progressed so far, that Lothar Meyer? and Mendeléeff? 
could express it in the form of the periodic system. But 
it was still somewhat fragmentary, that is to say while 
the periods were clearly recognized as such, there was 
a certain discrepancy in connecting them. In other 
words, there was a missing link, which was not found 
until the discovery of the rare gases by Ramsay, Ray- 
leigh, Travers and Cleve in 1894 and 1895. These ele- 
ments seemed at first to have no place in the system and 
aroused much controversy as to their position in the 
periodic system. But in spite of the fact that some, e. g. 
Dennstedt,' believed argon to be a kind of nitrogen—=N, 
(like ozone — O,) they were placed either in a new group, 
the zero group, or in the eighth group by Thomson,° 
Ramsay,*® Crookes’ and others. 

As Thomson has pointed out, the electropotential of 
these rare gases may be regarded as +0 or +o. Thus 
they form the connecting link between the periods, viz. 
the halogens and the alkali metals, and we obtain a con- 
tinuous line of elements when arranged with increasing 
atomic weights. 

But there was still some uncertainty as to the limits of 
the periodic system (compare Losanitsch*®) which was not 


* For references see the end of this paper. 


Am. Jour. Sc1.—Fourts Series, Vou. XLVI, No. 273.—SrepremBer, 1918. 
18 


482. Hackh—Modification of the Periodic Table. 


cleared up until the recent discovery of the high-fre- 
quency spectra of the elements by Moseley,® and the 
assignment of atomic numbers to the elements. From 
the work of Broglie,’® Hicks," and Rydberg,! and others 
we are now comparatively certain as to the relative 
atomic numbers of the elements and the spaces left blank 
by so far undiscovered elements. 

We can, therefore, proceed to establish the periodic 
system in a more rigid form. The customary table of 
Mendeléeff and Meyer is not correct, owing to the extreme 
difficulty of classifying the elements Nos. 59-72. If they 


eT 
6.0 | 7.N “8.0 OUR i@ie 


a “Tb 
11.Na_12 1 15.P° 16:8. SaeGe IIb 


puis 13.A 
32.Ge | 33.As 34.Se 35.Br| 36.Kr [IIIb 


| 50.Sn | 51.Sb_ 52.Te 53.1 | 54.Xe | IVb 


eLU 
82.Pb | 85.Bi_ 84.Po 85. 86.Nt_| Vb 
+ 


tool f+ ———> +9: too | 


TaBLE I. The periods of the system: Group O being the terminals, 
Group 4 being the transition points. 


are placed in the usual way, we would expect to find 
another rare gas between Xe and Nt; another alkali 
metal between Cs and No. 87; and so on—but we know 
that this is not the case, and the considerations of this 
paper will prove this. 

Many attempts have been made to harmonize these facts 
with the periodic system, either by means of ‘‘pleyads”’ 
= Ce, = Fe as proposed by Biltz,'* Buchner™ and others, 
or by subdivision into smaller groups, e. g. by RB. J. 
Meyer ;?® or by simply writing these elements into the 
different groups, without regard to their properties, as 
done e. g. by Brauner;!® or by the more convenient way 
of simply ignoring them and writing into the proper 
place of the system: ‘‘Ce ete.,’’ as is the usual and cus- 
tomary method of procedure. 

Our present knowledge enables us now to make the 
assumption that the rare gases are so to speak the ter- 


Hackh—Modification of the Periodic Table. 483 


minals of the periods. Beginning in any period with a 
rare gas, whose electro potential we consider to be + « 
we find that the elements following it change from posl- 
tive to negative until the period ends in a rare gas again. 
This is shown in Table I. It will be noticed that in this 
arrangement only the first four and last four members of 
the periods are recorded and that the elements of the 
carbon group form the transition line from a positive to 
a negative element. The elements of the carbon group 
may be regarded as the zero point in each period respec- 
tively. We have then in the first and second period one 
zero point each (C, Si) and in the third and fourth period 
two zero points each (T1-Ge, Zr-Sn), while the very long 
fifth period has three zero points. When we plot the 
relative position of the elements in the displacement 
_ series against the atomic numbers, we obtain the follow- 
ing interesting curve (p. 484). 

The displacement series was constructed from such data 
‘as offered by Wilsmore,'? Palmaer,'® Abege’® and those 
given in the Chemiker Kalender?® and Landolt Born-- 
stein.t. There are interesting analogies in this curve. 
The first six and the last seven elements of the four com- 
plete periods have similar positions; this makes thirteen 
elements whose position is determined. It is, therefore, 
clear that in the fifth period from X to Nt there can be no 
unknown rare gas with its. corresponding thirteen ele- 
ments; we must rather assume that, as the potential dit- 
ference between the first and last member in each group 
is the same, and divided among 7, 17, 35 elements, the 
_ difference in potential among the 35 elements is naturally 
very small and gives a group of very similar elements, 
that is the group of the rare earth metals. In other 
words the potential difference from Li to F, and from 
Na to Cl in the first two periods, is divided among seven 
elements. The potential difference from K to Br, and 
from Rb to I in the two long periods, is divided among 
seventeen elements, which show alr eady the formation of 
‘vertical’? groups (Mn-Fe-Co-Ni, ete jet int the ffth 
period this same potential is divided among 39 elements, 
thus forming naturally a very long group of elements in 
which the difference of their properties is very slight. 

A similar curve is obtained by plotting the maximum 
polar number of the elements against the atomic number 
as shown in fig. 2. The negative or positive polar num- 


"SJUOULITO OY} JO 9OLOJ GATJOWLOAZOO]O OALYL[OL ou Deore 


+N x 4 W 


| Saat | 


a 
¢ 


-= 
cco = — 
= 


= 


Modification of the Periodic Table. 
eee a 


Hackh 


‘T prq 


484 


485 


‘ogo ‘y-+ pue [— [0 ‘e+ pue e— N ‘6 ‘2 
‘@ jop v Aq pozeorput st toquinu zejod UNUILUIH eYy oLoyA\ “S[BJeTIUOM OY} OJ qdaoxe ‘(7 Sl lequinu qejog WNULLUTT, OU, 


‘syuetueTs 949 Fo Joquinu ABlOd WUNUIXeT, eT SG “Ory 


O06 og OL 09 OS OV O€ 02 Ol 


ab). 2) HL IS ) 


Hackh—Modification of the Periodic Table. 
QUI Con exe 9D = On f= 00 
tO. Cy 


‘Sg “DIY 


486 Hackh—Modification of the Periodic Table. 


ber of an element is the mathematical expression of 
their valence on the basis of oxygen = -—2, according to 
Bray and Branch.?? A table of all the polar numbers is 
given in Table II which gives also an indication of the 
character of the compounds. It will be noted that the 


oO 
BBWoZzaw 


Oo 


6 
7 
8 
9 
°) 
1 
2 
e) 


i 


Positive Polarnumbers of 

stable compounds 
nh" ,oxides of strong basic charac 

t f 1 weak " eter 
amphoteric 
weak acid 
strong acid 
unstable or little knovm compounds 


i} 
i 


uurunh wu 


Negative Polamumbers of 
mainly stable compounds. 


"OXIDATION" is the augmentation of the polarnumber, 
that is the increase in valency, while the reverse 
"REDUCTION" is the diminution of the polarnunber, 
e.g. the change from ferrous = 2 to ferric = 3, and 
from ferric = to ferrate = 6 is "oxidation", 


TasLE II. The polar numbers (valence) of the elements. 


first and second periods are analogous, also the third 
and fourth, while in the fifth we recognize in the begin- 
ning and end the analogy. The first five and the last 
eight elements of each period are similar to each other, 
as was exactly the case in fig. 1. 


Hackh—Modification of the Periodic Table. +87 


From these two generalizations of facts we are entitled 
to divide the elements into periods, similar to the divi- 
sions already proposed by Batschinsky,?? Werner,** 
Adams,2** Harkins,” and myself.2° We have, accord- 
ingly, the following periods: 


i from He to EF 8 =2 x 2? elements (first short period) 


peer Ne Cl gS «Sf (second “* ) 
geass or brilS=2 xX 3? * (first long period) 
eran, tks 5“ + (second ‘* ae) 
fee he 8592 = 2K 4? ae (very long period) 
Secs NG * U7 elements 


(together with H = 1 2? elements) 


The explanation for this periodic increase in the number 
of the elements between the rare gases must be found in 
the constitution of the atoms. That is to say that the 
positive and negative charges, or corpuscles, in the rare 
gases form a stable and neutral system. Let us indicate 
this stable system of negative electrons around the pos- 
itive nucleus as x, then this x must be 8 or a multiple of 8, 
for we have in the first period (according to Parson’s 
scheme ) 


Heidi Be B 6 N O F Ne 
g #+1 #42 2643 o4+4 @4+5 246 «47 248 = 20 


and so on for the other periods, e. g. the third period: 


2 ea ied ig Ca Se Abi. 
3x2 3xe+1 3844+2 32+3 382+4 
Ge As Se Br 4 Kr 
4¢+4 4¢7-+5 4¢+6 4¢+7 4¢+8 = Oe 


This would indicate that the atoms of the elements near 
the rare gases constitute more stable systems of elec- 
trons, and thus exhibit a more distinct characteristic in 
their properties. On the other hand the larger the num- 
ber of electrons becomes, the less rigid, and easier inter- 
changeable they become. The interchange of electrons 
may be illustrated by the remaining elements of the fifth 
pericd as follows: 


Ce eb derasolien es Sime eit Geb bo) Dy. - Ho 
Tz +4 5 6 7 8 Ge NOt: ahora. dS 
Sa + i 2 3 4 Dd 
Gx + 


488 Hackh—Modification of the Periodic Table. 


Kr ¢ Pm’ Tim”: Yo “ba Tas We aS Os aie 
te ++ D4” «15416 
82 + 6 7 8 9-510. SVD 4.32 8 & Bie ene 
9a + 1 2 3 4 5 6 7 8 


Au He Tl Pb 
On 9 1G. 12 210 
OG ro 


This indicates that e. g. the atom of gold is an equilibrium 
of the system 92 +9—10x%-+1 ete. It is outside the 
scope of this paper to treat the constitution of the atoms, 
and the above was mentioned in order to bring out the 
length of the different periods, together with the 3 impos- 
sibility of the existence of another rare gas between Xe 
and Nt. 

The next task is then to arrange these results in the 
best possible way. ‘There are numerous modifications of 
the periodic table, a proof that the table is not perfect. 
One of the main objections to the periodic table is the 
placing of the main and sub groups together in one col- 
umn; another, far more serious objection is that no 
indication is made of the different length of the periods. 
Table III will meet these objections, besides having 
other advantages. This table :was derived from a 
curve?" by the simple method of using the upper part of a 
spiral in its relation to the lower part like an image and 
its mirrored semblance. 

The ideal way of representing the periodic system is 
naturally a curve, which may take the form of a spiral 
drawn on a plane, or a helix constructed in space, as has 
been pointed out by Harkins.?* In the literature we find 
many such spirals, compare e. g. those of Reynolds,” 
Spring,*° Huth,?! Crookes,?? Houghton,?* Stoney,*+ Erd- - 
mann,’ Tocher,?® Hmerson,?? Rayleigh,?* Scheringa,®® 
Hack,*® Hackh,*! Rydberg,*? Soddy,* Bilecki,* Lorne 
Kunz** and others. But the more extensive use of those 
spirals is encumbered by the technical difficulties of 
reproducing them, and for this reason a table derived 
from a spiral and embodying its advantages is practical 
and useful. The table presented in this paper preserves 
not only those relationships among the elements which 
are expressed by the customary table of the periodic 
system, but illustrates also a number of new correlations 
among the elements. : 


Hackh—Modification of the Periodic Table. +489 


So, for example, the groups and subgroups of the ele- 
ments are clearly separated, bringing thus the respective 
elements closer together. From a study of the table we 
may draw the rule that the semilarity among the proper- 
ties of the elements in the upper half of the table 1s more 
pronounced in the vertical direction (analogy m groups), 


_ 


27 28 
Co Ni Cu Zn 
AD5 


46 | 47 
Rh Pd Ag Cd In 


58 Booee Gl 62. 657764, 165 566 67 G8 -69: 702 71 
Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm' Tm" Yb 


72 73 74 15 79 80 81 
Lu ia W Au 


90 3=(o9 92 
Th By U 


26 
Fe 
44 
Ru 


TaBLE III. The periodic table, showing groups and periods. 


while the sumilarity among the elements wm the lower half 
of the table is more pronounced in the horizontal direc- 
tion (analogy wm periods). Accordingly we may speak 
of group relations and period relations, e. g., the group 
relation of Au is in regard to Ag and Cu, while the 
period relation of Au is in regard to Hg and Pt. Or in 
other words, we may say, e. g., that the chromium group 
includes Cr, Mo, W, U; while the chromium period may 
embrace Cr, Mn, Fe, Co. 


490 Hackh—Modification of the Periodic Table. 


A classification of the elements into nonmetals and 
metals is easily made by considering the elements to the 
left of the rare gases as nonmetals, those to the right as 
light metals, and those in the lower half of the table as 
the heavy metals. The carbon group furnishes the tran- 
sition elements framing in the elements of the table and 
guiding from one line to the other. 

Among other general properties common to elements in 
certain areas of the table may be mentioned: 

The elements in the upper half of the table have the 
highest electro-potential, the simplest spectra, colorless 
ions and mostly soluble compounds, and possess mostly a 
single valence. 

The elements in the lower half of the table have a — 
lower electro-potential, complex spectra, colored ions and 
form complex double salts, and possess mostly more than 
one valence. | 

On the left side of the table are the electro-negative 
elements forming’ acids. 

On the right side of the table are the electro-positive 
elements, forming bases and oxysalts, sulphides, ete. 

In the center of the lower half are the amphoteric ele- 
ments, forming weak acids, weak bases, many compli- 
cated compounds and double salts, many insoluble and 
colored ions. 

A new and striking feature of the table is also the 
illustration of the somewhat notorious chemical affinity. 
This often criticized term affinity 1s employed to express 
the tendency or selective preference for certain elements. 
Such a tendency exists and is characteristic of certain 
regions in the table. We have for instance: 

Klements combining with nitrogen and forming typical 
nitrides are those around boron: 


Ca Se A, 
Mas Al 
Li Be | B 


Elements having a weak tendency to combine with » 
oxygen (the noble metals) are those neighboring gold: 


Ag 
Platin-metals Au Hg 


se = 


Hackh—Modification of the Periodic Table. 491 


Elements combining with sulphur, forming typical 
sulphides, are: 


Mar he Co “Nr Cu Zn Ga "Go" As 
Ae Cd" “Int “Sn Sb 
Poe Hoes) Pp Bi 


where the maximum of affinity is at Pd and decreases 
eradually toward Mn, which has the lowest affinity for 
sulphur.* 

The elements combining with hydrogen fall into two 
distinct areas: 

(a) The nonmetals, giving gaseous or liquid hydrogen- 
compounds in which hydrogen is positive. 

(b) The light metals, giving hydrides in the form of 
salts, with hydrogen being negative. 

Elements combining with cyanogen (CN’) and form- 
ing characteristic radicals and cyanid-ions also occupy 
neighboring places: 


Greer aim he “Cos Ni Cus 2m 
Mo — “Ru Rh: Pd Ae’ Cd 
Oo ir Get. An sa 


Typical ammoniae compounds are formed by the ele-- 
ments around nickel: 


Cor: Nas. Cay 
Pd Cd 
Pi 


These illustrations of the selective tendency or the 
chemical affnity among the elements could be multi- 
pled indefinitely, e. g., organometallic compounds, ete. 
Closely related to this is the polar number, already men- 
tioned, and the isomorphism. 

Table Il has shown the positive or negative polar 
numbers of the elements, and from it the periodicity of 
the valence is clearly shown. It appears that the last 


* The affinity for sulphur is given as follows: Pd Hg Ag Cu Bi Cd Sb 
Sn Pb Zn Ni Co Fe As Tl Mn, which forms a kind of a displacement series 
of importance in mineralogy; see Schuermann, Liebig’s Annalen, 249, p. 
326, 1888. 

Weed, Eng. & Min. J., 50, p. 484, 1890. 

Van Hise, U. 8. Geol. Surv. Monograph, 47, p. 1114, 1904. 

Buckley & Buehler, Missouri Bur. Geol., 4 (2d ser.), p. 90. 

Emmons, U. S. Geol. Surv., Bull. 625, 1917. 


492. Hackh—Modvrfication of the Periodic Table. 


four members of each period have polar numbers always 
two units apart, e. g., 1-3-5-7, 2-4-6, 1-3-5, 2-4, ete., while 
the polar numbers of the elements in the middle of a 
period are odd and even. A survey of their compounds 
show, that isomorphism is closely related to the polar 
number of the elements. Thus the table of isomorphism 
as given by Nernst can be completed as follows: 


Polar number 1: Li-Na-K-Rb-Cs; Cu-Ag-Pd-Au-Hg-TI. 

Polar number 2: Be-Mg-Ca-Sr-Ba; Zn-Cu-Ni-Co-Fe-Mn-Cr-V-Ti; 
Cd-In-Sn; Hg-Pb. 

Polar number 3: B-Al-Se-Y-La; Se-Ti- V-Cr-Mn-Fe-Co-Ni; 
Ga-In-Tl; La-Ce-rare earth, ete. 

Polar number 4: C-Si-Ti-Zr-Th; Ge-Sn-Pb; ete. 

Polar number 5: N-P-As-Sb-Bi; V-Cb-Ta. 

Polar number 6: 8-Se-Te; Cr-Mo-W-U; Mn-Fe; Ru-Rh; 
W-Os-Ty. 

Polar number 7: F-Cl-Br-I; Mn. 


We may take, for example, group 6, with the maximum 
polar number 6 and find the following general formulas 
for some of their compounds: 


—2:H,X = Hydrogen-x-ides, where X is 8-Se-Te. 

+4:X0, + H,O0 = H,XO, = x-ites, resp. their salts where X 
ean be practically each element. 

+ 6:X0O, + H,O = H,XO, = x-ates, resp. salts. 


thus we have sulphates, selenates, tellurates, chromates, 
manganates, molybdates, tungstates, uranates, ferrates, 
ete., etc., in all of them X being hexavalent. Fig. 3 illus- 
trates this relationship. We may e. g. take the bivalent 
and trivalent elements and find two distinct series of com- 
pounds: the metall-ows compounds, erystallizing all 
with 7 mol. of H,O and commonly known as the vitriols of 


(Ti) (V) Cr Mn Fe Co Ni Cu Zm Me(Be) 
Mo Rh Pd Cd 
(W) Ir Pt 


all of them being soluble and forming double salts with 
the elements of group 1. On the other hand we have the 
metall-ic compounds of the simple formula M.(SQO,);. 
12H,O which forms the well-known series of alumes 
XM ( SO,), .24H,.O where X is a monovalent ae or 
NH,’ and M a trivalent element, either 


Hackh—Modification of the Periodic Table. 493 


Piatt GaccAl Sef VV; Cr. Mn.Ne...Co 


In both cases we have seen that the elements occupy 
neighboring positions in the table, and the connecting 


Big. 3. 


AES) SRR 
wails 


3 
caer 
BRIA 


3 Pe 
= 


K 
4 
Na : 


HHZIE 
pelle Greene 


° Gore dine tine ob ee Se 


fe a3 
An 
2346 


eae 
EISEN 


~ Fie. 3. Polar number and Isomerism of the elements. 


medium is its polar number. The closer the elements 
stand to each other, the closer are its properties related 
to each other. 

We may take, for instance, the chlorides of any A- 
group, say LiCl, NaCl, KCl, RbCl, CsCl and we find, as is 


494. Hackh—Modification of the Periodic Table. 


well known, close relationship not only in regard to their 
forms of crystallization, their solubility, their melting- 
points, but also in regard to their chemical behavior and 
stability. This periodicity can be extended to the mono- 


Nt Th 
Bi 20 


Mo 
06 |9.01 peas be ia fae REY ae Teds 


teat 
Nd Sm | Eu Gd | Tb | Dy | Ho Er | Tm “Yb | Lu 
6.7| 6.5| 6.9 7.8 


1 cc H,O at 18°C, 760 mn = 1,00 


TABLE IV. The specific gravity of the elements (calculated to H.O = 1). 


chlorides of Cu, Ag, Au with the addition, however, that 
in the lower half of the table the similarity along periods 
dominates the similarity along groups; therefore the 
properties of these chlorides, CuCl, AgCl, AuCl, will be 


Hackh—Modification of the Periodic Table. 495 


more affected by the period relation than the group rela- 
tion. Thus we find that CuCl and AgCl, while still stable, 
are less soluble and ionized, while AuCl is unstable and 
hydrolyzes with water forming Au and AuCl,, this latter 
chloride being more stable and closely related to PtCl,, as 
should be expected from the rule given above. 

To give further illustrations of this rule of ‘‘vertical’’ 
resemblance in the upper half, and ‘‘horizontal’’ resem- 
blance in the lower half of the table, is unnecessary; an 


metallic as non-metallic 
oa 33, Arsenic ; 34, Selenium 


erst.- cristallinic amph.- amorphous 
metl.- metallic mnel.-monoclinic 
liqu.- liguid 


TaBLE V. The allotropic forms of some nonmetals, showing the position 
toward the metallic side. 


examination will make this self-evident. It should be 
pointed out, however, that by the separation of the ele- 
ments into their ak and B groups, the periodicity of their 
properties is more clearly exhibited and one can grasp 
the increasing or decreasing tendencies of these proper- 
ties ina more convenient and shorter way. A very good 
illustration is furnished by Table IV, showing the specific 
gravity of the elements. The arrows indicate the 
increasing density, which follows the arrows with the 
exception of some elements of the first period, in a strik- 
ing manner. It is well known that in a given group of 
elements the metallic character increases with increasing 


496 Hackh—Modification of the Periodic Table. 


density and this fact can even be extended to the allo- 
tropic forms of the elements. Table V represents a 
section of the main table in which the density of the 
allotropic forms of some elements are placed. These 


a 
a 317.4 336 .6|1076 |160 oo 2068 
Na Mg SI 
$71.01 90a2 - 111687 
C 
i fee 3090 iB: 


Mn 
fee ne on 1530 ne >, e ae 1231 


Ag In 
iors oe sis as sai ee 1234.4 sl A428 


Ce | Pr | Nd Sm[Eul |Gd]Tb/ Dy! Ho Er |Tm Yb 
896 |1210 600 (Gener 2 2 ? 7 
110 ? 2170 
Ta W Os | Ir Pt Au Hg Tl “es 
3120 | 3540 2970 | 2670 | 2028/1335 .5| 234.28] 574.8 |600.5 
pa U e ; ; : 


2700 T= Ut - 273.13 


> >< 39 € K€ € €< 


TABLE VI. Melting points of the elements (absolute degrees). 


allotropic forms are so placed that they follow the gen- 
eral direction of increasing density and the result is, that 
the more metallic allotropes come toward the carbon 
group, which forms the transition to the metals, while the 


Hackh—Modification of the Periodic Table. 497 


allotropic forms of a nonmetallic character are placed 
toward the halogen group, thus fitting very well into the 
system. The melting points given in Table VI follow 
not so generally a certain direction, nevertheless their 


aa ea | 7A aa | 4 _| 


83 85 ee 87 89 an _ == 
Bi oo Ac By 


Disintegration takes place in 
two ways: 


€— ~ alpha-radiation, indi- 
cati loss of He-atom ; 


C the elements becomé more ele- 
212 tro-positive and the atomic 
AcC eet decreases by 4, 


A = beta-radiation, indi- 
cati loss of electrons : 
the elements become more 
electro-negative, the atomic 
weight remains the same. 


RaA 
218 


2 Io U 
226 wa ZaQUe a \os4 
Ss 


Isotopes of the elements with 
atomic number 81-92 are the 
substances mentioned in the 

vertical colums. The number 
of isotopes Bre Tn at the 
bottom of the table. Thus e.g. 
Pb has 7 isotopes. 


TABLE VII. System of radioactive elements, from thallium to uranium. 


periodicity is. better exhibited than in the old table. 
I have used the table in keeping a permanent record of all 
the numerical data about the elements; each property that 
can be expressed in a numerical value has its own table, 
and I have found this method very satisfactory and 
better than the customary alphabetical tables. New 


Am. Jour. Sci.—FourtTH Series, Vout. XLVI, No. 273.—SepteMBER, 1918, 


498 Hackh—Modification of the Periodic Table. 


determinations are constantly added and the reference 
recorded. In doing this work, I was surprised to find 
how very fragmentary our knowledge is; with the excep- 
tion of the specific gravity and the melting point, which 
are known of nearly every element, there are hardly any 
data of properties in the literature for more than forty 


Pb Bi 
PbRa —— RaF 


Ra 
PbTh\ 7 The! 
PbAc AcC' 
RaD : 


see) 
te: <—{Ict) 
AcA 
RaB RaA 


TABLE VIII. The complete periodic system (elements and isotopes). 


elements; most of those are limited to twenty and even 
ten elements. There is still a great field open for physi- 
eal determinations of element- constants. 

The isotopes of the radioactive elements are given in 
Table VII, in which the three series of disintegration, 
e. g., uranium, actinium, thorium, are combined into one. 
It will be seen, that with the exception of the beginning of 
these series, the disintegration of all three series is analo- 
gous from the isotopes of thorium (RaTh, RaAc, Io) to 


Hackh—Modification of the Periodic Table. 499 


the isotopes of lead (PbTh, PbAc, RaD). The connec- 
tion between the uranium and actinium series is doubtful 
(U-Uy-Uz-Ac) and indicated by a broken arrow. The 
other series begin as follows: 


U-Ux’-Ux” (Bv)-U,-Io-Ra, ete. 
Th-MsT’-MsT”-RaTh-ThX, ete. 
Ac-RaAc-AcX, ete. 


At the bottom of the table are given the number of known 
isotopes and their atomic weights. The atomic weights 
of the isotopes of the longest life periods are underlined, 
while the missing atomic weights of the actinium series 
are indicated by an arrow. A regularity in the atomic 
weights is naturally to be expected and clearly seen from 
a study of the table. 

This table of the radioactive elements can be attached 
at the bottom of the main table, or as done in Table VIII, 
these elements may be put in brackets, indicating their 
isotopes, and also their group-relationship, indicated by 
horizontal or vertical lines respectively. 

An exhaustive treatise on the periodic system is in 
preparation, of which this paper is intended to be a 
preliminary statement. 


CoNCLUSION. 


1. By plotting the elements, as to their atomic num- 
bers against their relative position in the displacement 
series, a periodic curve is obtained, in which a similarity 
among the element groups and periods exists. (Fig. 1.) 

2. A similar periodicity is shown by the polar num- 
bers of the elements (fig. 2); accordingly the elements 
are divided into two short, two long and one very long 
period. 

3. From both curves it can be predicted that no new 
rare gas can be discovered, because such a new element 
would demand characteristic properties of about thirteen 
other elements, and of these thirteen elements none is 
known, or in other words, no known element between the 
atomic numbers 63 and 76 exhibits these characteristic 
properties. Therefore all the elements of the electro- 
potential + wo are known. 


500 Hackh—Modification of the Periodic Table. 


4. In establishing a more rigid form of the periodic 
system these elements (He, Ne, A, Kr, X, Nt) are used as 
the starting and ending points of the periods; between 
these terminals the properties change periodically, and 
the more elements there are between (fifth period), the 
less characteristic is the change. This accounts for the 
formation of such groups as Fe- Co- Ni, Ru-Rh-Pd, Os-Ir- 
Pt, and the rare earths. 

5. The periodic system is best expressed in a con- 
tinuous curve, e. g., spiral. But as such graphic repre- 
sentations are difficult, a table has been derived which 
shows the relationship among the elements better than 
the customary table. A number of characteristic fea- 
tures of the table have been pointed out and the rule 
established that: The Similarity among the elements 
in the upper half of the table is in a vertical direc- 
tion, while the similarity among the elements in the lower 
half is in a horizontal direction. 

6. The term affinity is vindicated, when its use is 
restricted to a characteristic tendency of the elements in 
a certain area of the new periodic table. 

7. A table showing the close relationship ‘between 
polar number and isomorphism is presented. 

8. The periodicity of the specific gravity is shown in 
Table V and the allotropic forms of the elements are 
introduced into the periodic system by Table VI, repre- 
senting a section of the main table. An accumulation of 
more facts regarding the allotropic forms of other ele- 
ments will justify an enlarged table, giving also the tran- 
sition points. 

9. A condensed system of the radioactive elements has 
been constructed (Table VII) which can be used as an 
appendix to the main table (Table VIII). 


Berkeley, California. 


REFERENCES. 


Chem. News, 13, pp. 113 and 130, 1866. 
7 Ann. Chem. Pharm., 7, 354, 1870. 
* Journ. Russ. Phys. Chem. Ges., 1, pp. 60 and 229, 1869. 
*Chem. Zeitg., 19, p. 2164, 1895. 
°Z. anorg. Chem., 9, pp. 190 and 283, 1895. 
* Ber., 31, p. 3111, 1898. 
Ae anorg. Chem., 18, p. 72, 1898. 
© Die Grenzen des periodischen Systems, Belgrad, 1906, and Ion, 1, 259, 
SAO: 


Hackh—Modification of the Periodic Table. 401 


® Phil. Mag., 26, p. 1024, 1913. 

Compt. rend., 159, p. 304, 1914. 

Pio, Mac., 28, p. 139, 1914. 

Paul. Mag., 28, p.. 144, 1914. 

% Ber., 35, p. 562, 1902. 

144 Ber., 46, p. 422, 1915; also Chem. Weekbl., 12, p. 336, 1915. 

1 Naturwissenschaften, 2, p. 781, 1914. 

16 Z, Elektrochem., 14, p. 525, 1908. 

uw 7, Hlektrochem., 7, p. 254, 1900; also Z. phys. Chem., 35, p. 291, 1900. 

18 Festschrift Nernst, p. 332, 1912. 

1 Handbuch der anorg. Chem., ITI, 2, p. 2, 1907. 

arehem. Ial., IT, p. 333; 1915. 

1 Phys. Chem. Tabellen, p. 1208. 

2 J. Am. Chem. Soe., 35, p. 1440, 1913. 

*87Z. phys. Chem., 43, p. 372, 1893. 

4 Ber., 38, p. 914, 1905. 

*“a J. Am. Chem. Soc., 33, p. 648, 1911. 

J. Am. Chem. Soc., 38, p. 169, 1916. 

°° Weltwissen, 3, p. 63, 1915. 

* Hackh,. Das Synthetische System der Atome, Hamburg, 1915. 

8 J. Am. Chem. Soc., 38, p. 169, 1916. 

*° Chem. News, 54, p. 1, 1886. 

 Ber., 29,°p. 3092, 1886. 

** Periodische Gesetz, Berlin, 1887. 

* Chem. News, 78, p. 25, 1898; also Proc. Roy. Soc., 63, p. 408, 1898, 
and Z. anorg. Chem., 18, p. 72, 1898. 

* Chem. News, 58, pp. 93 and 103, 1888. 

* Phil. Mag., 4, p. 411, 1902; also Chem. News, 57, p. 163, 1888; and 
Proc. Roy. Soc., 46, p. 115, 1888. 

* Lehrbuch der anorg. Chem., Beilage. 

“Pharm J., 84, p. 159, 1910. 

* Am. Chem. J., 45, p. 160, 1911. 

*8 Proc. Roy. Soe., 85, p. 471, 1911. 

*° Chem. Weekblad, 8, p. 389, 1911. 

® Erklarung der chemischen Wertigkeit und periodischen Regelmassigkeit 
des elements durch ein model, Hamburg, 1913. 

* Weltwissen, 3, p. 63, 1915. 

* Rev. geh. sci., 25, p. 734, c/o Chem. Abstr., 9, p. 540, 1915. 

“Le Radium, 11, p. 6; also in Chemistry of the Radioactive Elements, 
part 2, p. 11, 1915. 

= Cnem. Zentr., 2, p. 1, 1915. 

Chem. News, 111, p. 157, 1915. 

“ Orig. Com., 8th Int. Congr. Appl. Chem., 22, p. 187. 


502 - Kryshtofovich—Cretaceous Age of the 


Arr. XVIII.—On the Cretaceous Age of the ‘‘ Miocene 
Flora’ of Sakhalin; by A. N. Krysurorovics.! 


The following pages form a summary of the results of 
the elaboration of a part of plant fossils collected on 
Sakhalin Island during 1917, the balance of the collec- 
tions having been shipped to Petrograd. 

The fossil flora of the island of Sakhalin comes chiefly 
from two localities, Dui and Mgach. It was described 
originally by Heer? in 1878 who referred it to the Mio- 
cene. Since it is rather extensive it has usually been taken 
as a type for purposes of comparison with other Tertiary 
floras despite the presence of Nilssoma, a genus quite 
unusual in Tertiary deposits. No doubts as to the Ter- 
tiary age of this flora have been expressed except that 
on purely geological grounds Messrs. Tikhonovich and 
Polevoi® have suggested recently that the Dui series (and 
consequently its flora) was of considerable older Tertiary 
age than the Mgach series, which is also characterized by 
a rich flora, and which they regarded as belonging to the 
Miocene. The matter of special interest is that Nilssoma 
was believed to be a member of this Mgach flora. 

Having been despatched by the Comité Géologique in 
1917 to Sakhalin, I have been able to prove that the fossil 
flora of Sakhalin does not belong merely to the Miocene 
or Tertiary, but comprises several different horizons 
from the Miocene down to the Cenomanian and in 
part probably still more ancient. Heer unfortunately 
described mixed collections from Mgach, where, as I 
noticed, the exposures of plant-bearing Cenomanian and 
Miocene beds outer op close together, although the two 
are unconformable, a fact which Schmidt and other 
explorers failed to observe. The predominance of speci- 
mens collected in the upper Tertiary exposures in the 
Heer collection convinced him that the whole flora was 
Tertiary. However, the presence in my collections made 
at this locality of Dammara borealis, Protophyllocladus 
subintegrifolius, many ferns, cycads and typical Angio- 


1 Communicated and edited by Prof. Edward W. Berry. 
Puen 1878, Die Miocene Flora der Insel Sachalin, i. foss. Arct., vol. 


5, pt. 
earmonoricn and Polevoi, 1915, Geomorphological Sketch of Russian 
Sakhalin, Mémoires de la Comité Géologique, Russia, vol. 120 (new series). 


““Miocene Flora’’ of Sakhalin. 503 


sperms, all collected in lower coastal outcrops, as well as 
the entire absence of any of these in the flora of upper 
exposures, leads me to regard the former as really 
Cretaceous. 

The paleobotanical explorations along the sea shore 
to the south and to the north from the capital of Russian 
Sakhalin, Alexandrovsk, disclosed many Cretaceous out- 
crops, not yet fully determined. 

The presence of the Cretaceous flora in Sakhalin is 
particularly important because in Russia as well as in the 
countries of the Far Kast we have only meager Creta- 
ceous floras of Angiosperms, notwithstanding that Cre- 
taceous rocks are widely distributed, as was recently 
noticed by Berry in the description of the Lower Cre- 
taceous of Maryland. Except some fossil woods and 
Lower Cretaceous forms from the Province of Moscow,?* 
and the Ryoseki flora of Japan,> we know but one Angio- 
sperm flora from Ural Provincee,® one leaf of Cretaceous 
Platanus conf. Heer Lesg. from Turkestan,’ and some 
plants from Hokkaidd, mostly preserved as petrified 
fragments.* In a subsequent paragraph I will indicate 
that some floras of Siberia, hitherto believed to be Ter- 
tiary, partly even Miocene, must be regarded rather as 
Cretaceous after the present elucidation of the composi- 
tion of the vegetation during the Cretaceous period in 
Sakhalin. 


Geological sketch of the area. 


In addition to the Paleozoic rocks, without any organic 
remains except Radiolaria, and chiefly limited in the 
eastern part of Sakhalin, the Russian Sakhalin, espe- 
cially its western part, is made up of Cretaceous, Terti- 
ary and Postplocene deposits. Former interpretations 
of the geology of the island, based upon the plant 
fossils, may now be regarded as wrong. 

Orographically in this part of Sakhalin the Coast 


* Trautschold, 1876, Der Klin’sche Sandstein in Russland, Nouv. Mémoires 
de la Soe. Imper. des Nat. de Moscou, vol. 13, p. 191. 

° Yokoyama, 1894, Mesozoic Plants from Kozuke, Kii, Awa, and Tosa, 
Jour. Coll. Imp. Univ. Rokyo, vol. 7, .p.:3. 

* Kryshtofovich, 1914, The discovery of the Angiosperm Flora in the 
Cretaceous of Ural Province, Bull. de 1’Acad. Imper., 1914, p. 603. 

*Romanowsky, 1890, Materialien zur Geologie von Turkestan, vol. 3, 
pr. Lao. 

“See Stopes, 1913, The Cretaceous flora, Bibliography. 


504 Kryshtofovich—Cretaceous Age of the 


Range stretching from the Japanese frontier terminates 
somewhat to the south of Alexandrovsk, in Cape de la 
Jonquiére, being limited by the Gulf of Tartary on the 
west and by the graben of Dui river (Alexandrovka) on 
the east. In the same direction but farther toward the 
north stretches the Western Range. This mountain 
chain is separated by the Coast Range from the sea shore 
to the south from Alexandrovsk. Farther to the north 
the country is quite open from the sea. According to the 
testimony of the animal fossils the median part of the 
Coast Range consists chiefly of the Cretaceous, especially 
its upper series, which further to the east is interrupted 
by the fault along the left bank of Alexandrovka river. 


‘The Cretaceous here contains sandstones with conglom- 


erates as well as the dark slate with coal, and character- 
ized by both faunal and floral remains. ‘This is overlain 
without discordance by the Lower Tertiary with two beds 
of conglomerate at the boundary, in turn intercalated 
with the coaly shales the age of which is not yet deter- 
mined although some fossil plants were collected at this 
horizon. We observe the Cretaceous further to the east 
beyond the valley of Alexandrovka, where it appears on 
the slopes of the Western Range. Here it is also coal 
bearing and at least a part of it represents a more ancient — 
series, characterized only by the fossil plants and lacking 
the fauna found associated with plants in the Coast 
Range. As I have observed, the whole western slope as 
far~as Cape Khoi is made up of the same Cretaceous 
partly unconformably overlain by the younger Tertiary. 
In the same area, somewhat to the northeast from Alex- 
androvsk, are exposed the most ancient known Creta- 
ceous strata of the region, characterized by a flora of 
ferns—mainly Gleichenia. 

According to the differences indicated by the floras 
represented at the different horizons of the Cretaceous, 
and having in mind the presence of the Senonian Jnocera- 
mus fauna? in the upper beds, I propose dividing the 
Cretaceous into the following three series: I, Upper 
or Orokkian Series: II, Middle or Gyliakian Series; 
TIT, Lower or Ainuan Series. 


° Sokolow, Kreideinoceramen des russischen Sachalin. Mém. de la Comité 
géol., n. s., livr. 83, St.-Pétersb. Also Schmidt. 1873, Ueber die Kreide 
Petrefacten von Sakhalin, Mém. Acad. Sci. St.-Pétersb. (7) vol. 19, No. 7; 
Yabe, 1909, Zur Straticraphy und Paleontologie der oberen Kreide von 
Hokkaido and Sachalin, Zeitschrift der Deutsche Geol. Gesell., vol. 61, p. 402. 


“Miocene Flora’’ of Sakhalin. 505 


The Tertiaries are represented by Older and Younger 
series called respectively the Dui and Megach series by 
Tikhonovich and Polevoi (op. cit.). The Lower series or 
Dui series takes a prominent part in the composition of 
the Coast Range, being concordant with the Cretaceous. — 
It consists of sandstones and slates partly marine with 
shells, but chiefly coal-bearing and containing the best 
quality of coal in Sakhalin which can be compared only 
with the English Cardiff and the best Japanese Taka- 
shima coal. The series is exposed chiefly on the sea 
shore and has not been observed out of the boundaries of 
the Coast Range. It is pierced by eruptive rocks and 
intercalated by several basaltic sheets and tuffs. 

The Mgach or Younger Tertiary series consists of a 
coal-bearing division below and is represented in the 
upper part by loose shales and sandstones containing 
marine shells. To this series belong the slow burning 
non-coking coals worked at Mgach. This Younger Series 
also fills the graben of Alexandrovka and noncon- 
formably overlies the Cretaceous to the north of Alex- 
androvsk, where no traces of the Lower Tertiary Dui 
series were observed. 


The Paleobotanical evidence. 


The younger horizon of the Cretaceous developed in 
the Coast Range is particularly interesting, since it con- 
tains representatives of both the fauna and flora at Cape 
dela Jonquiere. The whole appearance of this broad leaf 
flora overlaid by Inoceramus and Ammonites horizons 
is so recent that Schmidt, influenced by Heer’s determina- 
tions, erroneously regarded this bed as true Tertiary and 
inverted; just as he believed similar inverted conditions 
of exposures of beds containing an Angiosperm flora and 
typically Cretaceous fauna in the island of Vancouver. 

In addition to the fact that the flora of Cape dela Jon- 
quiére is not of the usual Tertiary type, the rich Creta- 
ceous fauna of Ammonites, Helcion, Inoceramus, etce., 
fixes the age of this horizon as Senonian, thus giving us a 
knowledge of a true Senonian flora in the extreme East 
of Asia. 

In some exposures on the slopes of the Western Range 
and on the sea shore to the north from Alexandrovsk I 
have found a flora of more archaic appearance that must 
be regarded as representing a more ancient horizon 


506 Kryshtofovich—Cretaceous Age of the 


although without associated invertebrate faunas. Thus 
the three established Series of the Cretaceous in Russian 
Sakhalin, the Orokkian, Gyliakian, and Ainuan, may be 
florally characterized as follows: 


I. The Orokkian. This series is chiefly characterized 
by broad leaved types besides a few ferns and some 
conifers, from which I have as yet identified only 


Asplenium dicksonianum Heer 
Sequowa smittiana Heer 
Populus arctica Heer 
Credneria sp. 

Hedera mcclurwu Heer 
Viburnum schmidtianum Heer 


Il. The Gyltakian flora, very rich and varied, and 
studied in more detail by me, contains 


Dicksonia mamiyai n. sp. 

Asplenium dicksonianum Heer 
Pecopteris virginiensis Fontaine*® 
Pecopteris cf. bohemica Corda? 
Pteris frigida Heer 

Stenopteris jambot n. sp. 
Sagenopteris variabilis (Vel.) Velen. 
Cycas steenstrupu Heer 
Glossozamites aff. schenckw Heer 
Nilssonia serotina Heer 

Ginkgo sp. A. 

Ginkgo sp. B. 

Protophyllocladus subintegrifolius (Lesq.) nee 
Dammara borealis Heer 

‘Sequoia reichenbachwu (Gein.) Heer 
S. fastigiata Sternberg 

Thuja cretacea (Heer) Newberry 
Populus arctica Heer 

Cocculus aff. extinctus Velenovsky 
Credneria aff. integerrma Zenker 
Bauhina cretacea Newberry 
Celastrophyllum yokoyamat n. sp. 
Aralia polevow n. sp. 

A. tikhonovichw n. sp. 
MacClintockia sachalinensis n. sp. 


IiI. The Ainuan flora, studies in less detail, shows 
only the following species: 


* Referred by Berry to Cladophlebis browniana (Dunker) Seward. 


“* Miocene Flora’? of Sakhalin. 507 


Gleichenia rigida Heer 

G. zipper (Corda) Heer 
Gleichenia sp. 

Asplenium dicksonianum Heer 
Populus ef. potomacensis Ward 


The general composition of these floras and the 
presence in the youngest horizon of an Ammonite fauna 
compels me to regard the whole flora as undoubtedly Cre- 
taceous. However, its different horizons show some 
peculiar features. Thus the flora of the uppermost 
series, the Orokkian, shows a younger aspect, and might 
very readily be mistaken for Tertiary on account of con- 
taining many species common in the so-called Arctic 
Tertiary floras of Greenland, Spitzbergen, etc. but 
searcely anything is common to the latter and the true 
Tertiary flora of Sakhalin. The undoubted Cretaceous 
age of the Sakhalin floras listed above and the presence 
in them of elements characteristic of the ‘‘Arcto-Ter- 
tiary’’ flora leads me to suggest a revision of the age of 
the latter, which may be really even older than the similar 
floras in Sakhalin, on account of their more northern 
position, if the migration of floras was really from the 
north. : 

The characteristic form of Orokkian, Populus arctica, 
has not yet been found in the Dui series (though it oceurs 
in the lower Tertiary flora of Onnenai in Japanese 
Sakhalin) but it is abundantly represented in the Gylia- 
kian together with some typical Cretaceous plants. I 
regard this horizon as an equivalent of the Patoot of 
Greenland, and being not very different in age from the 
prebasaltic deposits of Atanekerdluk, the latter undoubt- 
edly Cretaceous and not Tertiary as it has been hitherto 
considered. Thus the age of this Series may be taken as 
Senonian and possibly partly Turonian. 

The flora of the Gyliakian is very rich in ferns resem- 
bling those of the Atane and Dakota floras and partly 
those of the Patapseco formation. Several cycads also 
suggest those of the Atane beds of Greenland and the 
Cenomanian of other countries. The Conifers and the 
Angiosperms are also very typical of the Cretaceous, 
especially of the Raritan and Dakota, e. g., Protophyllo- 
cladus. Dammara, Bauhinia cretacea; Aralia polevoi is 
very similar to Araliaephyllum magnifolium of the 
Patapsco; Celastrophyllum yokoyama closely resem- 


508 Kryshtofovich—Cretaceous Age of the 


bles the Celastrophylla of the Dakota. Sagenopteris 
variabilis and Cocculus affinis are common in the Ceno- 
manian of Bohemia, and Aralia tikhonovichit is repre- 
sented there by a closely allied species. Having many 
features common with the Cenomanian flora of Europe, 
the Gyliakian flora is, however, more closely allied to 
those of North America and Greenland. If in making 
more close comparisons with the American Cretaceous 
floras we notice that the Gyliakian flora has some ele- 
ments of the Patapsco flora, its resemblance with those 
of the Dakota and Raritan is more striking. The pres- 
ence in the Gyliakian of Populus arctica, not yet discov- 
ered in the Atane beds or even in some younger (in 
which, however, it was probably recorded under some 
other names) also compels me to correlate the Gyliakian 
with the younger rather than the older, and I am there- 
fore inclined to regard it as the equivalent of Dakota, 
Raritan and Atane, being Cenomanian and probably 
partly Turonian. Thus the paradoxal presence of the 
Nilssoma of real Mesozoic aspect in the ‘‘Mgach Flora’’ 
of Heer is quite simply explained, and the botanists must 
give up the hope of finding it still living somewhere in 
China as was expressed by some of them on account of its 
supposed existence as late as in the ‘‘ Miocene Flora’”’ of 
Sakhalin. 

The flora of the Ainuan Series shows very few features 
of resemblance either with the upper or Orokkian flora or 
even with that of the Gyliakian Series, being represented | 
mainly by ferns, in part not yet determined. There are 
only a few remains of a Populus of primitive aspect 
identified by me as Populus ef. potomacensis Ward which 
occurs in what is probably an uplifted horizon of this 
series. I believe this flora corresponds to the Kome 
flora of Greenland as it is not younger than Albian, but 
the complete investigation of it 1s not yet made. 

The importance of correctly determining the age of the 
Sakhalin fossil floras may be understood when it is 
recalled that in all Asia there have not before been known 
any upper Cretaceous floras except single remains men- 
tioned in my introductory paragraphs and some petrified 
specimens hardly comparable with the flora of impres- 
sions of other countries, and presenting therefore insuf- 
ficient materials for judging the evolution of the flora in 


Asia. 


““Miocene Flora’’ of Sakhalin. 509 


The Cretaceous flora now discovered in Sakhalin 
becomes still more remarkable if we remember that its 
upper horizon shows associated with the flora a rich 
fauna which can be correlated not only with those of 
Hokkaido but even with the more distant fauna of Hin- 
dustan and Vancouver. On the other hand the flora 
itself, representing a considerable interval of time, fills 
the gap hitherto existing between Europe and America in 
the ring of the floras around the North Pole, the supposed 
center of origin and migration of the Angiosperm flora. 

When completely elaborated the Mesozoic flora of Sak- 
halin, since it is extensive and its upper limit is fixed in 
age by the associated fauna, may furnish a helpful scale 
for the revision of age of the Arctic floras and those of 
Canada, on account of presence in the Orokkian of such 
species as Populus arctica, Hedera mccluru, etc., believed 
to be Tertiary in the above mentioned floras. In addition 
there are numerous floras scattered all over the vast 
Siberian expanse and hitherto without a good scale for 
the judging of their age. Already after a preliminary 
study of the Sakhalin flora I decidedly put into the rank 
of the Cretaceous the flora of Simonova!! as _ being 
older than the uppermost horizon of this system. Still 
younger but undoubtedly Cretaceous appear some floras 
in Amurland partly described previously as Tertiary. 
One of the latter, namely the flora of Boguchan mountain 
near Sagibova on Amur river, I put into the Cretaceous 
in 1916. Others may represent the transitional floras 
corresponding to the Laramie of western North America. 
-On the other hand, the true Tertiary flora of Sakhalin is 
rich in species and also represents several horizons. 
Freed from the unfortunately admixed Cretaceous ele- 
ments it also may be taken as a good seale for com- 
parison with the Siberian floras, especially on account 
of the intercalation of the flora of the Dui series in Sak- 
halin with several faunal horizons. Some interesting 
deductions may also result from the comparison of the 
Sakhalin floras with those of Japan. 

The following diagram represents the relation of the 
Sakhalin Cretaceous floras to those best known in the Old 
and New World :?” 


1 Heer, 1878, Beitrage zur foss. Flora Sibiriens und des Amurlandes, 
Fl. foss. Arctica, vol. 5, part 2. 

2 American and European correlations taken from Berry, E. W., Lower 
and Upper Cretaceous floras of the World, 1911 and 1916. 


Kryshtofovich—Cretaceous Age, ete. 


510 


(uvdep) tyesodAy 


({BiQ, Yynos) aLutay,-uouep[n yy 


(goutAord resstue x ) BAOUOUITG 


uBypus0g 


LAY Boing 


uBnULy 


wery erp Ay) 


ULIYYOLO 


SOT}I[BOO] OIPBISY IOIO 


UI[BVYYVG UBISsnay 


ouvyy 


40078] 


quexnye UBLULODOS NT 
JLOPSU.1O 
jopun.tw 
UIT ST UBIULILILE 
WIS LBULV ueydy 
UeTaTy: 
oosdvye SBI[Od 
UVILLBY 
Z4N.10q 
ea Ga UBLUBULOUOAD) 
BIOYVC | VUIOYOS.OpoOLN 
3.19 UISSTO AA 
AYJOSBIN, 
a7 aoe ae ZILULB IN UBIUO.L YT, 
zt do, 
BIVAQ OTN UdSOTI 
SOTA So UBLUOUVg 
OLUIBIET UvIUB 
BoLLouLy adoangy | 


Kirk—Paleozoic Glaciation in Alaska. 511 


Art. XIX.—Paleozoic Glaciation in Southeastern Alaska; 
by Enwin Kirx.* 


Evidence of glaciation in the Paleozoic is of interest 
even though the discovery of tillites has become the com- 
monplace of geologic field work. During the past field 
season a tillite of Silurian age was found in southeastern 
Alaska. This is particularly interesting as being the 
first record of Silurian glaciation. Fairly conclusive 
evidence of Permian glaciation was also secured. There 
is some reason to believe that glacial deposits occur in 
the Devonian of the region as well. 

Cairnes in 1914 described a conglomerate of ‘‘Permo- 
Carboniferous?’’ age which he found on the Alaska side of 
the international boundary just north of 65° north latitude. 
He considered the conglomerate as possibly of glacial 
origin. The conglomerate has a thickness of 700 to 800 
feet and his description leaves little doubt but that it is a 
true tillite. One of his arguments against the probable 
elacial origin of the beds is that no other deposits of like 
character are known in Alaska. This objection has been 
met by the discovery of conglomerates in southeastern 
Alaska that apparently hold the same stratigraphic posi- 
tion and have most of the characteristic features of till- 
ites. The conglomerate described by Cairnes has been 
accepted by Coleman as a tillite without question. Apart 
from this discovery of Cairnes no other paleozoic glacial 
deposits have been reported from Alaska. 

The Silurian conglomerates which have proved to be of 
glacial origin were first noted by the Wrights! in their 
bulletin on the Ketehikan and Wrangell mining districts, 
Alaska. They were given an estimated thickness of 
1200 feet and were placed within and at the base of the 
- Lower Devonian. No special description of the con- 
glomerates was given by the Wrights and no suggestion 
of possible glacial origin was made. These conglom- 
erates are a conspicuous feature of the area on the west 
coast of Prince of Wales Island bordering on Davidson 
Inlet and Sea Otter Sound. The conglomerates are 
found seattered over an area of some 200 or 500 square 


* Published by permission of the Director of the U. S. Geological Survey. 
1 Wright, F. HE. and C. W., U. S. Geol. Survey, Bull. 347, 1908. 


519 Kirk—Paleozoic Glaciation im 


miles in this immediate region, and further study would 
no doubt considerably extend the range to the south, east, 
and north. The best exposures of the Silurian elacial 
beds seen were on Heceta Island, although good outcrops 
are to be found on the south shore of Kosciusko Island, 
about 15 miles to the north. Apparently the same beds 
occur along Ei] Capitan passage betwen Kosciusko and 
Prince of Wales islands. At the north end of Kuiu 
Island, some 125 miles to the north, a bowlder bed holds 
the same stratigraphic position and, I believe, represents 
the same glacial deposit. Kosciusko and Heceta islands, 
where the best Silurian glacial deposits are to be found, 
he between 55° and 60° north latitude, and 133° and 134° 
west longitude. These islands are situated on the west 
coast of Prince of Wales Island, toward the northern end. 
Prince of Wales Island is the large island of the south- 
eastern Alaska group, the southern point of which just 
clears the Alaskan-Canadian boundary. Kuiu Island 
hes to the north and slightly west of Prince of Wales 
Island. 

The most favorable locality for an examination of the 
conglomerate is in the large bay about midway on the 
north shore of Heceta Island. The coast here is well pro- 
tected from storms and there is a continuous. outcrop of 
the hmestone underlying the conglomerate, the conglom- 
erate itself, and the overlying limestone. In places the 
conglomerate is well broken down by weathering, making 
the collection of pebbles and bowlders an easy matter. 
As exposed, the beds outcrop along the shore between tide 
levels and give an outcrop perhaps 2000 to 3000 feet in 
length. The beds strike about N. 30° W. and have an 
average dip of about 30° N.E. At the east end of Heceta 
Island, on what is locally known as Blue Bluff, several 
hundred feet of the conglomerate are exposed in an 
abrupt face together with the basal portion of the over- 
lying limestone. Both this exposure and that on the — 
south side of Kosciusko Island are difficult of access 
except under exceptionally favorable weather conditions. 

The glacial conglomerate is underlain and overlain by 
fossiliferous marine limestones. The succession of beds 
is clearly shown and unmistakable. The same relations 
can even more clearly be seen on the bold cliff at the east 
end of Heceta Island as to the upper limit of the conglom- 
erate. The relations of the conglomerate to the under- 


Southeastern Alaska. 513 


lying limestone are well shown on Kosciusko Island. The 
strata as a whole in this region are badly disturbed and, 
as is the case throughout southeastern Alaska, contacts 
are very poorly shown, being as a rule indicated by an 
indentation of the shore line and a depression running 
back into the timber. At present, therefore, although 
the relative positions of stratigraphic units are obvious, 
the character of the unconformity and the nature of the 
passage beds are only partly known. 

The limestone series overlying the conglomerate car- 
ries a rich Conchidiwm fauna. In certain thin beds the 
rock is almost wholly made up of the brachiopods. This 
fauna appears to be identical with that of the limestone 
near Meade Point at the northern end of Kuiu Island. 
At the base of the limestone at this locality is a bowlder 
bed which I believe to be glacial in origin and to be cor- 
related with the conglomerate of Heceta. The lime- 
stones below the conglomerate likewise carry a rich fauna 
consisting of pentameroids, corals, and gastropods. 
The general aspect of both faunas seems to place them 
as approximately late Niagaran in age. 

The conglomerate itself has a thickness of between 
1000 and 1500 feet. It will probably be found to vary 
considerably from place to place. In the main the con- 
olomerate appears to consist of heterogeneous, unstrati- 
fied or poorly stratified material. Rarely lenticular 
bodies of cross-bedded sandstone occur in the mass. 
These are clearly water-laid and indicate current action. 

The bowlders in the tillite range in size up to 2 or 3 feet 
in length, as seen. They consist of greenstone, gray- 
wacke, limestone, and various types of igneous rocks; 
limestone bowlders are scaree. All the bowlders are 
smoothed and rounded. Facetted bowlders are numer- 
ous, and given the proper type of rock, characteristic 
glacial scratches are common. The scratches show best 
on the fine-grained, dense greenstones. Limestone bowl- 
ders and certain types of igneous rocks do not show them 
at all.~ The shore line is strewn with these pebbles and 
bowlders which were undoubtedly derived from the con- 
glomerate as they are not to be found on the adjacent 
limestone shores. All the material collected was taken 
from the conglomerate itself. This is well broken down 
by weathering in some places, and the pebbles may be 
picked out with the fingers or tapped out with the ham- 


Am. Jour. Sct.—Fourts Series, Vou. XLVI, No. 273.—SmpremBer, 1918. 
20 . 


514 Kirk—Paleozoic Glaciation in 


mer. When fresh the conglomerate as a rule is massive 
and exceedingly hard. 

The nature of the deposit is such as to suggest a till. 
The heterogeneous character of the bowlders, both as 
regards size and material, and the apparent lack of strat- 
ification in the main, point to a true till rather than a 
submarine bed of ice-transported glaciated material. 
Such evidence as is at hand indicates that the Heceta area 
was very near the shore line and might easily have been 
land while the glacial material was being deposited. 

The question of interglacial periods in the Silurian of 
the region can not at present be discussed with any 
degree of certainty. The finer points of stratigraphic 
succession are not known owing to the complex structural 
relations, the poorly shown outcrops, and the apparent 
lateral variation in character of sediments. I believe, 
however, that there are several distinct bodies of tillite 
separated by marine sediments. At the old Haida vil- 
lage of Klnkwan on the southwest coast of Prince of 
Wales Island and a few miles north of the west shore of 
Klakas Inlet are what I take to be beds of tillite inter- 
bedded with Silurian graptolite shales. The same con- 
dition obtains on the east shore of Dall Island in the 
neighborhood of View Cove. These tillites and shales 
I believe come above the limestone series overlying the 
tilite on Heceta Island. On Heceta Island itself, unless 
there has been considerable repetition by faulting, which 
does not seem probable, two or three distinct beds of 
tillite are indicated. 


PERMIAN GLACIAL DEPOSITS. 


In Pybus Bay, Admiralty Island, and on the Sereen 
Islands off the west shore of Etolin Island are conglom- 
erates strongly suggesting glacial material. In both 
cases these overlie high Carboniferous beds which have 
been correlated by Girty with the Gseshelian. Overlying 
the conglomerates are Upper Triassic beds. Where seen 
the conglomerates had not weathered down and it was not 
possible to obtain loose bowlders which might show 
scratches; facetted bowlders occur in the conglomerate, 
however. It will probably be found that this is a true 
glacial deposit and to be correlated with the conglomerate 
described by Cairnes near the Alaskan-Canadian boun- 
dary. A conglomerate similar to that described- above 


Southeastern Alaska. 515 


underhes the upper Triassic rocks of Dall Head, Gravina 
Island, and may prove of the same age and of similar 
character. 

The occurrence of Permian glacial deposits in Alaska 
is of special interest inasmuch as most of the reported 
occurrences of tillites of this age have been in the 
tropics or to the south of the equator. Alaskan gilacia- 
tion coupled with that near Boston, Mass., the two being 
possibly synchronous, indicate widespread glacial con- 
ditions in North America during this time. A con- 
glomerate in southwestern California of approximately 
the same age is worth noting. This conglomerate is 
described in a U. S. Geological Survey Report, now in 
press, on the geology of the Inyo Range, California, by 
Adolph Knopf and Edwin Kirk. This conglomerate is 
composed of ill-assorted pebbles and bowlders and car- 
ries contemporary potholes. Sandstones and conglom- 
erates, probably to be correlated with this conglomerate, 
extend widely through Utah and Nevada and possibly 
correlate with the Weber. A careful study of these sedi- 
ments offers interesting possibilities in the way of adding 
to our knowledge of land and possibly glacial conditions 
in Permian times. 


PossIBLE DEVONIAN GLACIATION. 


In the Stringocephalus-bearing limestone zone of the 
Middle Devonian small facetted pebbles up to 214 inches 
in length are of fairly frequent occurrence at one locality 
on the west coast of Prince of Wales Island. In Fresh- 
water Bay and in Port Frederick, which lie near the 
northern end of Chicagof Island some 250 miles to the 
north, conglomerates occur in the Lower or Middle 
Devonian. Rounded bowlders up to 2 feet in diameter 
were seen. They are very unlike normal sedimentary 
conglomerates. Should the bowlders in the Devonian 
prove glacial, a somewhat different origin would probably 
be postulated for the conglomerates themselves. These 
are thin, ranging in thickness up to 25 feet or so, and 
would be more easily explained perhaps as consisting of 
berg-borne material, though glacial in origin. Bottoms 
of a similar nature are even now to be found in the chan- 
~ nels of southeastern Alaska. 


U. S. Geological Survey, Washington, D. C. 


516 Grout—Lopolith; An Igneous Form 


Art. XX.—The Lopolith; an Igneous Form Exemplified 
by the Duluth Gabbro; by Franx F. Grovt. 


CONTENTS. 
Introduction. 
Possible forms of the Duluth gabbro, and early ae 
The laccolith. 
The lopolith. 
General remarks on the Duluth gabbro. 
Summary. 


Introduction.—The several students of the Duluth gab- 
bro as a formation have had several opinions as to its 
form and relations. Recent descriptions refer to it as a 
laccolith, though it differs from the typical laccoliths in 
some details. Several other large intrusions are of sim- 
ilar form, and it is here suggested that the form deserves 
a special name. The size and relations of the Duluth 
mass are summarized. 

Possible forms of the Duluth gabbro, and early sugges- 
tions.i—In 1883, R. D. Irving referred to the gabbro as 
probably the reservoir from which the Keweenawan flows 
came. N. H. Winchell, in several papers from 1880 to 
1910, refers to the ‘‘great basal flow’’ and later to bosses 
and intrusive masses. Bayley, as late as 1893, quotes 
Irving that it is ‘‘not intrusive in the ordinary sense,’’ 
but says it might be a succession of thick flows or the 
reservoir from which the flows came. Grant, in 1900, and 
others more recently have described it as a laccolith. 

The intrusive character of the gabbro is clearly shown 
at Duluth.2 It has as definite a roof and floor as a lac- 
eolith or sill, and was intruded along a surface approxi- 
mately corresponding to a previous structure,—the 
unconformity at the base of the Keweenawan. On the 
basis of its banded structure one may estimate the posi- 
tion of its floor. This eliminates the probability of any- 
thing funnel like or particularly irregular,—it is not like 
the “ethmolith”? or ‘‘chonolith.’? Thus it comes about 
that by a process of elimination the gabbro is placed with 


‘Trving, R. D., Copper bearing rocks of Lake Superior: U. 8S. Geol. Surv., 
Mon, 5, pp. 144, ete. 

Winchell, N. H., Minn. Geol. and Nat. Hist. Survey, Ann. Rept. 10, p. 
114, 1881; Final Rept., vol. 4, and vol. 5. 

Grant, U.S., Minn. Geol. and Nat. Hist. Survey Final Rept., vol. 4, p. 326; 
and Bull. Geol. Soe. America, vol. 11, p. 505, 1900. 

*Grout, F. F., Paper at the December (1917 ) meeting of the Geological 
Society of America. 


Exzemplified by the Duluth Gabbro. “Holey 


the laccoliths. It is best, however, to review the defi- 
nitions and usage of the term laccolith. 

The laccolith—The laccolith as originally defined by 
Gilbert? is insinuated between strata (or along the plane 
of some previous structure) with a flat floor and an 
up-domed roof; its thickness ranges around one-seventh 
its width, and its ground plan is nearly circular. Several 
- geologists, after wide experience with intrusive masses 
elsewhere, have found it convenient to shghtly modify the 
definition to include clearly related masses.t Thus, the 
concordance with previous structure is not always per- 
fect, but a general tendency is characteristic; the form 
also may be somewhat unsymmetrical. Laccoliths grade 
into sheets on one hand, and into ‘‘bysmaliths’’ with 
faulted uplifted roof, on the other. It seems to have 
been agreed that the magma was aggressive in uplifting 
its roof, stretching the overlying beds and separating its 
roof and floor; Harker even coined the name ‘‘ Phaco- 
lith’’ for similar forms which might be attributed to other 
forees.® 

Several large intrusions are known which differ from 
laccoliths in having a sunken rather than a domed roof; 
in fact, some are so thick that a roof could not have been 
held up, isostatically. The masses are now in the form 
of great saucers or basins. The process of intrusion was 
probably very different from that of a laccolith. In spite 
of the fact that each of the several examples has in recent 
years been described as a laccolith, it is difficult to formu- 
late a definition to include both types. For example, 
Daly gives an excellent summary of current usage, and 
defines a laccolith as plano-convex or doubly convex.® 
Later he calls the larger concavo-convex masses lacco- 
liths, frankly admitting that they are departures from the 
type. 

This being the case, Professor Joseph Barrell has sug- 
gested that as igneous forms they deserve a distinct 


* Gilbert, G. K., Report on the geology of the Henry Mountains, U. S. 
Geol. and.Geog. Survey of the Rocky Mountain region, pp. 19, 53 and 55. 

*Geikie, A., Structural and field Geology, p. 190. 

Iddings, J. P., Igneous rocks, vol. 1, p. 314. 

Harker, Alfred, Natural history of Teneous Rocks, p. 65. 

Pirsson, ibe ue and Schuchert, Charles, Text book of Geology, Dtsel, 
p- 297 

°C. R. Keyes, however, now argues for a different mechanism for the 
true laccolith, December (1917) meeting of the Geol. Soc. of America. 

®° Daly, R. A., Igneous Rocks and their Origin, p. 70. 


518 Grout—Lopolith; An Igneous Form 


name. Such a name is better based on the known facts of 
form or relations than on any theory of origin, and the 
name proposed by the writer is ‘‘lopolith”’ (from oras, 
a basin, a flat earthen dish, and /@os, a stone).* 

The lopolith. —A lopolith may be defined as a large, 
lenticular, centrally sunken, generally concordant, intru- 
sive mass, with its thickness approximately one-tenth 
to one-twentieth of its width or diameter. Most of the 
known lopoliths are in part of basic rocks, and probably 
because of their large size and slow cooling have 
differentiated notably. They may show the varying 
degrees of complexity described as ‘‘multiple,’’ ‘‘com- 
posite,’’ ‘‘divided,’’ ‘‘interformational,’’ as distinguished 
from ‘‘simple.’’ The type departs from a laccolith, not 
only in form but in the probable mechanics of its 
intrusion. 

The Duluth gabbro with its differentiates is one of the 
best illustrations of a lopolith. At Duluth the roof and 
floor dip east. The crescentic outcrop, concave toward 
Lake Superior (see fig. 1), dips in all parts toward the 
lake. The assumed eastern border of the lopolith is con- 
cealed under other rocks and under the lake, but the 
sheet of gabbro on the Gogebic range dips north even 
more steeply than the Minnesota mass dips south. It is 
thus somewhat unsymmetrical, but clearly sunken in the 
center. Its cross-section is also clearly lenticular. The 
overlying rocks are mostly Keweenawan flows, and 
though the horizon of the roof may vary some hundreds 
of feet, the discordance is unimportant when compared 
to a lateral extent of about 150 miles. The base of the 
gabbro rests on such a series of formations from Archean 
to Keweenawan, that the first impression is one of com- 
plete discordance with earlier structure. However, if 
the intrusion transgressed the earlier structure, it is a 
remarkable coincidence that the two ends, now outecrop- 
ping 140 miles apart, and the southern outcrops almost as 
far to the south, all transgressed up to exactly the same 
horizon. This coincidence is not the only difficulty in the 
assumption of a transgressing intrusion. After the bor- 
ders had transgressed to the Keweenawan, the central 
parts of the intrusion which must have been in the 
Archean, must have stoped their way up to exactly the 
horizon to which the border was first intruded; we now 


* Pronunciation, 16’polith. 


Exemplified by the Duluth Gabbro. 519 


Fie. 1. 


Me Red Rock above it 


20! Sandstone 


d 
Shope ees 


Fic. 1. Map of the west end of Lake Superior showing Keweenawan areas. 


520 Grout—Lopolith; An Igneous Form 


find the roof at a fairly constant horizon. The magma 
must have spread along an unconformity, or we are 
forced to the absurd conclusion that the magma knew 
when to cease its stoping. Another fatal objection to the 
idea of transgression and much stoping, is the volume of 
material missing. The Rove slate, where it dips under 


Hie. 2: 


Thick Strong 


alr gle 


Lape 
So Lopolish © re 


Fie. 2. Sketches to suggest the possible relation of a mace to the other 
forms of occurrence of igneous rocks. 


the gabbro, is estimated to be 2600 feet thick, 7 and this is 
only one of several missing formations. Hall has esti- 
mated that the slates west ‘of the gabbro are 20,000 feet 
thick, 5000 feet in sight.2 The estimates are not based on 
accurate data, but are probably of the right order of 
magnitude. These formations could easily have been 


7 Van Hise, C. R., and Leith, C. K., Geology of the Lake Superior region; 
U. S. Geol. Survey, Mon. 52, p. 201. 

® Hall, C. W., The Kewatin of eastern Minnesota: Bull. Geol. Soc. 
America, vol. 12, p. 374, 1901. j 


Exemplified by the Duluth Gabbro. 521 


eroded in the long pre-Keweenawan interval,®? but could 
hardly have been stoped into the gabbro, no matter what 
the horizon of intrusion. It seems certain, therefore, 
that the gabbro was intruded and spread approximately 
along the base of the Keweenawan. 

Besides the Duluth mass as a type, one might classify 
aS lopoliths the Sudbury and Bushveldt masses; and 
possibly the basin-like mass on the Isle of Skye and the 
banded rock of Julianahaab, Greenland. 

As a piece of speculation it may be of interest to sug- 
gest a relation between laccoliths and the larger lopo- 
hths; and note what would result from a continued 
increase in size. Figure 2 is self-explanatory. 

General remarks on the Duluth gabbro.—If the form of 
the Duluth gabbro is as assumed, certain consequences 
may be stated. The form being roughly lenticular, it 
seems probable that the extent down the dip is nearly as 
great as the length of an eroded outcropping edge. EHKven 
if it is only half that extent, a glance at the map indicates 
that it is very probable, as Van Hise and Leith mention,” 
that the gabbro of the Gogebic range in Wisconsin is part 
of the same original lopolith. 

If a roughly circular outline is drawn around all the 
known outcrops, it encloses over fifteen thousand square 
miles, the area once occupied by the lopolith; besides 
which it is evident that a part has been eroded, and prob- 
able that the subsidence which tilted the gabbro in Wis- 
consin to an angle of more than 75°, was accompanied by 
a good deal of crustal shortening. The present area of 
gabbro outcrops may be much less than the original. 

Estimates of the thickness may be made on the assump- 
tion that the floor of the gabbro dips approximately with 
the adjacent internal structure.11 The estimates are only 
approximate because of a scarcity of outcrops where the 
gabbro is widest, and because in the same region there 
are some thick sills which are distinguished with dif- 
ficulty from the gabbro. The maximum thickness indi- 
eated-in Minnesota is about 50,000 feet; at Duluth about 
12,000 feet are exposed; at the northeastern outcrops in 
Minnesota the lopolith is less than 3000 feet thick. These 
estimates are conservative in the matter of dip,—former 


®*'Van Hise, C. R., and Leith, C. K., op. cit., p. 208. 
7 Op. cit; P..57 0. 
-orout, FB -Op. cit, 


522, Grout—Lopolith; An Igneous Form. 


records of structure would indicate nearly twice as steep 
a dip as that here used.‘?, In Wisconsin the thickness of 
the gabbro is probably less than 4,000 feet.1* If the lopo- 
lith is thickest in the center like a lens, the real maxi- 
mum thickness is concealed below the lake. 

The volume of the lopolith may be estimated at over 
00,000 cubic miles. It is evidently one of the largest 
known intrusive masses. Considered with some related 
intrusions,—the Logan sills, the sills at Beaver Bay, and 
other intrusions of the same age in more distant parts of 
the Lake Superior region—it indicates an immensity of 
intrusive action at this time, that has rarely been 
equalled. 

Summary.—Certain large, centrally sunken intrusions 
are given a distinct name, lopolith. Lopoliths differ from 
laecoliths not only in these points of size and form, but 
probably also in the mechanics of their intrusion. The 
Duluth gabbro is a multiple, composite, divided lopolith 
which is furthermore interformational over most of its 
length. Conservative estimates of its size indicate an 
area of over 15,000 square miles, and a volume of over 
50,000 cubic miles—one of the largest known. floored 
intrusions. Other illustrations of lopoliths are sug- 
gested. 

Acknowledgments are here gratefully given to the 
members of the geologic staff of the graduate faculty at 
Yale University, for very helpful suggestions. 


a invaner hE De ope Clb. peec0o. 
18‘Van Hise, and Leith, op. cit., p. 377. 


Butts—Geologic Section of Pennsylvania. 523 


Arr. XXI.—Geologic Section of Blair and Huntingdon 
Counties, Central Pennsylvama,;* by Cuaries Burts. 


The geologic section in Blair and Huntingdon counties, 
Pa., was worked out by the writer in 1908 in a survey of 
the Hollidaysburg quadrangle and in 1913 in a survey of 
the Huntingdon quadrangle, which adjoins the Hollidays- 
burg quadrangle on the east. These two quadrangles 
include a large part of the two counties and lie across two 
great folds, the Nittany anticline and Broad Top Moun- 
tain syneline. The strata exposed have a maximum 
thickness of over 27,000 feet and an average thickness, as 
shown in the accompanying section, of nearly 25,000 feet. 
This is probably as thick as any if not the thickest section - 
exposed in the Appalachian region in so small an area. 

Geologists familiar with the region will see that the 
writer’s contributions to the stratigraphy consist partly 
of detail, such as the delimitation of the Middle and 
Upper Devonian formations recognized by the geologists 
of the Second Geological Survey of Pennsylvania but the 
boundaries of which were not defined by them. Much 
that is new has, however, been added, particularly con- 
cerning the lower part of the section, where the valley 
limestone, No. 2 of the older geologists, has been split up 
into twelve formations and several members. 

Brief notes, mainly on the new formations and their 
names, follow. In the Chemung the name Saxton con- 
glomerate member is introduced to replace White’s name 
Lackawaxen conglomerate, as it seems very uncertain 
whether this conglomerate is the same as the Lacka- 
waxen. ‘The conglomerate is well exhibited in and about 
Saxton, Huntingdon County, whence the name. 

The Portage group has been divided into two forma- 
tions, the Brallier shale and. the Harrell shale which 
includes, in the bottom, the Burket black shale member. 
The Brallier shale is named from a station on the Hunt- 
ingdon & Broad Top Mountain Railroad a few miles 
northeast of Everett, in Bedford County. This shale is 
the same as the Woodmont shale member of the Jen- 


* Published by permission of the Director of the United States Geological 
Survey, with the statement that parts of the classification and nomenclature 
have not yet been officially adopted. All the names of formations and 
members shown in the stratigraphic column have, however, been adopted 
by the Survey. 


524 Butts—Geologic Section of Blar and 


nings formation of Maryland, except that the Woodmont 
extends down to the Burket black shale member, regarded 
by the Maryland Survey as Genesee. The Brallier is 
well exposed and. can be most conveniently seen along the 
Pennsylvania Railroad west of Altoona and just east of 
Huntingdon. The Harrell shale is perfectly distinct 
lithologically from the Brallier, as shown by the deserip- 
tions of the section. In the Broad Top Mountain syncline 
in Huntingdon County the Harrell is about 250 feet 
thick and consists of soft, dove-colored fissile shale 
and interbedded layers of black fissile shale. In Blair 
County, to the west, however, the black shale is all im the 
bottom and is about 75 feet thick, the soft, dove-colored, 
highly fissile (paper) shale, about 200 feet thick, being 
free of black shale and forming the upper part of the 
Harrell. The name is taken from Harrell, a station on 
the Petersburg branch of the Pennsylvania Railroad, 
about midway between Hollidaysburg and Williamsburg 
where the dove-colored shale is well displayed. This 
shale is also well shown in a cut of the Pennsylvania. 
Railroad in the western outskirts of Altoona and in the 
brick yard at Eldorado, a few miles south of Altoona. 

The black shale member of the Harrell is named from 
Burket, a suburb of Altoona. The Burket member is 
well exposed in and about Altoona, at several places 
southwest of Altoona for 20 miles, and along the Penn- 
sylvania Railroad between Altoona and Bellwood. As 
already stated, this shale has been regarded as Genesee, 
but it carries no distinctively Genesee fossils; on the 
other hand, it and the overlying part of the Harrell gen- 
erally contain a good representation of the Naples fauna, 
found at the base of the Portage in western New York. 
The Burket is, therefore, believed to be basal Portage 
rather than Genesee. 7 

Just below the Harrell shale there is, in places at least, 
a limestone about a foot thick, from which were obtained 
Chonetes aurora and a Martinia like one of those of the 
McKenzie River region of Canada, which are there also 
associated with the same Chonetes. As Chonetes aurora 
is a characteristic fossil of the Tully limestone of New 
York, to which it appears to be confined, the thin lime- 
stone here is probably the feather edge of the Tully 
extending in an embayment into this part of Pennsylva- 
nia. If so the limestone really belongs in the Upper 


Huntingdon Counties, Central Pennsylvania. 525 


Devonian instead of in the top of the Hamilton, as placed 
in the section. 

The name Reedsville was introduced by Ulrich (Revi- 
sion). The formation corresponds about to the upper 
half of the Martinsburg shale. The top sandstone 
member, with Orthorhyncula, etc., is 30 to 56 feet thick, 
and extends without change from central Pennsylvania 
to New River, Va. Orthorhyncula was found also at Gate 
City, Va., near the Tennessee line. It is an extremely 
valuable horizon marker. 

The Trenton lhmestone here is said to agree well in 
character with the Trenton nearer its type locality. 

The Rodman limestone is new and is named from Rod- 
man, a station on the Pennsylvania Railroad near Roar- 
ing Spring, several miles south of Hollidaysburg, Blair 
County. This formation is only about 30 feet thick but 
is persistent throughout Nittany Valley and is identical 
in character and thickness in Center County and in Blair 
County. It can be seen in any of the quarries of the 
region, where it immediately overlies the quarry rock 
from which it can easily be distinguished by its litho- 
logic character and by the fact that it outcrops at the 
top margin of the quarries on the side toward the dip. 
The Rodman carries a considerable and an interesting 
assemblage of fossils which may be listed in a future 
paper. Echinospherites occurs in a zone of beds at Belle- 
fonte, Pa., between the Lowville and Trenton, of identical 
character and in part at least contemporaneous with the 
Rodman. Ulrich regards the beds in this zone as upper 
Black River and as falling within the scope of the 
Chambersburg limestone as defined in the Mercersburg- 
Chambersburg folio. It is not yet decided whether this 
EKichinospherites zone is to be identified with the upper or 
the lower of the two Echinospherites zones of that region 
but Ulrich is at present inclined to identify it with the 
lower. The fauna of the Rodman is not the same as that 
of the Sinuites bed in the base of which is the upper 
occurrence of EKchinospherites, while it contains forms 
that are so far known only in the lower Echinospherites 
zone. In the complete section these two zones are sep- 
arated by almost 400 feet of limestone. 

Ulrich thinks the Rodman may be the same as the 
Niskey limestone of Wherry, in the Lehigh Valley, but in 


526 Butts—Geologic Section of Blar and 


view of the uncertainty regarding their equivalence the 
local name is here used. 

The Lowville limestone is regarded as good typical 
Lowville. Fossils are comparatively scarce but so far as 
known the fauna is thoroughly in harmony with the litho- 
logic criteria on which the correlation was originally 
based. 

The Carlim lhmestone is new, named from a quarry 
town on the Petersburg Branch of the Pennsylvania Rail- 
road a few miles northeast of Williamsburg, Blair 
County. 

The Lemont member of the Carlim is named from - 
Lemont, near State College, Center County. 

Both the Carlim and the Lemont member are well dis- 
played in all the quarries of the region, the part of the 
Carlim below the Lemont member, with the Lowville 
overlying the Lemont member, being the main quarry 
beds of the region, which supplies a large part of the flux 
rock for the Pittsburgh blast furnaces. The Lemont is 
not utilized except for road metal or concrete, and con- 
siderable bodies of it remain in quarries where the flux 
rock has been taken out. 

The main body of the Carlim is very epoca fossil- 
iferous, but the Lemont member is locally richly so. <A 
few of the species are listed in the description of the sec- 
tion. Maclurites magna has not been found in Blair 
County but is common at Lemont. The Carlim 3s of 
middle Chazyan or middle Stones River age and corre- 
sponds about to the Lenoir limestone of east Tennessee, 
the Ridley of central Tennessee, and the Crown Point 
lhmestone of the Champlain Valley, in northeastern New 
York. 

The names of the Canadian formations Bellefonte, 
Axeman, and Nittany, were introduced by Ulrich in his 
‘‘Revisions of the Paleozoic Systems’’ in 1911. They 
were taken from Bellefonte, Center County, and vicinity. 
The formations in Blair County agree in all respects with 
the same formations in Center County, except that the 
Bellefonte and Nittany are each only about half as thick — 
in Blair County as m Center County. There is an 
exposure of nearly the full thickness of the Bellefonte 
and Nittany along the river a mile northeast of Williams- 
burg. 

The divisions of the Ozarkian and their names are all 


Huntingdon Counties, Central Pennsylvania, 527 


new, although the presence of the Ozarkian in this region 
was recognized by Ulrich in 1909 or 1910. 

The Larke dolomite is named from Larke postoffice, 
which is several miles south of Williamsburg, in Blair 
County, where thick beds of the dolomite are exposed. 
A good specimen of Helicotoma umangulata was found 
im the Larke near Ore Hill, farther west in the county, 
and shows that it contains beds, perhaps in its upper 
part, of the age of Ulrich’s Chepultepee dolomite of Ala- 
bama, of the Gasconade limestone of Missouri, and of the 
upper cherty, fossiliferous zone of the Little Falls dolo- 
mite of the Mohawk valley of New York. Good expos- 
ures of the Larke occur just east of Williamsburg. 

The Mines dolomite is named from the old mining town 
of Mines, which is several miles southwest of Williams- 
burg, where brown iron ore was once extensively mined 
by the Cambria Steel Co. This formation seems to occupy 
the position of the Copper Ridge dolomite of Ulrich, 
which in Tennessee is the main body of the Knox dolo- 
mite, lying between the Canadian (Beekmantown) part of 
the Knox and the Nolichucky shale. The Mines dolomite 
is best exhibited in the north end of the long ridge just 
southeast of Williamsburg, Pa. 

The Gatesburg formation is named from Gatesburg 
Ridge, in Center County, Pa., the name having been pro- 
posed by Prof. E. S. Moore, of State College. 

The Ore Hill and Stacy members were named by the 
writer. The Ore Hill is named from a mining town south 
of Roaring Spring, Blair County. This member has 
yielded several species of trilobites, mostly undescribed 
forms, the nearest relatives of which, according to Ulrich, 
occur in the Hoyt limestone of New York. The Ore Hill 
is well exposed in a quarry a mile southwest of Ore Hill 
and at a point just north of the road a half mile north- 
west of Drab in the Huntingdon quadrangle, 614 miles 
southwest of Williamsburg. Most of the fossils were 
collected at these localities. The Stacy member is named 
for Stacy Hill, an isolated knob 4 miles slightly west of 
south of Wilhamsbure. 

The Gatesburg is nowhere well exposed but can best be 
seen on the north bluff of the river, a mile northeast of 
Williamsburg and along the north bluff a short distance 
west of Williamsburg. It is also well exposed along the 


528 Butts—Geologic Section of Blair and 


main line of the Pennsylvania Railroad between Birming- 
ham and Shoenberger. 

The Gatesburg is correlated by Ulrich with a group of 
dolomite formations in central Alabama, lying between 
Ulrich’s Copper Ridge dolomite and the top of the Con- 
asauga limestone, the upper part of the Conasauga being 
regarded as the equivalent of the Nolichucky shale. 
These formations are the Briarfield dolomite of Ulrich, 
the Ketona dolomite, and some overlying beds of dolomite 
called Potosi by Ulrich in his Revision. The Larke, 
Mines, and Gatesburg should probably be correlated in 
general with the Conococheagne limestone of the Cham- 
bersburg and Mercersburg regions of Pennsylvania. 

The Warrior limestone is named from Warrior Creek, 
in the northern part of Huntingdon County, east of 
Warrior’s Mark. This limestone has been called the 
Buffalo Run limestone by Walcott (Smithsonian Miscel- 
laneous Collection, vol. 64, p. 165), who adopted, without 
definition, the field name used provisionally by Prof. 
Moore. The best exposures of the Warrior limestone 
are at the type locality on Warrior Run, along the river 
bluff a mile west. of Williamsburg, and in the western 
half of Bloomfield township, Bedford county, several 
miles south of Roaring Spring and on the Everett quad- 
rangle. 7 | 

The Pleasant Hill limestone is named from Pleasant 
Hill church a mile northwest of Henrietta, in the south- 
east corner of Blair County, where the upper part, the 
limestone, is excellently exposed. Ulrich regards both 
the Warrior and the Pleasant Hill as Upper Cambrian 
and Walcott regards the Warrior as Upper Cambrian. 
Probably the Warrior and Pleasant Hill are in part rep- 
resented by local beds of relatively pure limestone that 
have been somewhat doubtfully included in the upper 
part of the Elbrook limestone of Maryland and Penn- 
sylvania. 

The mapping of these limestone units has resulted in 
the detection of a number of hitherto unknown faults, 
some of considerable magnitude in both displacement and 
linear extent. For example, there is a great fault or 
narrow belt of overlapping faults of several thousand feet. 
displacement extending from the northwestern part of 
Hopewell township, Bedford County, northward to Birm- 
ingham, on the main line of the Pennsylvania Railroad, 


529 


a. 


Central Pennsylvan 


Huntingdon Counties, 


"YINOS SUTYOOTT—"}02F 0009 OF OOOG St Morqy orydersrye.ys 
ou “e[PPrur oy} Ut W0I40q oY} 4e Uses 9G Ud UOTJvULWIeXO [nZorvD Aq Ynq SutInjovry puv Ssutyutol Aq pornosqo st surp 


-peq U7, “OF ynoqe Fo drip ysvo uv YIM pouInyI0AO ‘ose IOATY Sou0JG o[pptu 10 wedzeYH opp ‘UITTAVO SE UOpPpLt0Ao 
QUOJSOUN] OJIYM OUT, FO, oyy 4B UooS oq Ud SuIppoqg oyy, ‘ouvd 4neFz 943 YAIAd JorTeavd ,GT ynoqe pavmysvo Sutddrp ‘ose 
ueLiquiey teddy Jo ‘auoqySOWIT AOTIIVM OTB SYOOI YSNAIYJAIOAO OY, ‘“oUOJSoUTTT oyLyYM OY} FO doz oY} 4e 4[NVF YsnayJA9AO UB 
surmoys “eg ‘uvysurmiig jo ysvo ysnl pvoarey vruvatdsuuog 94} FO OUI, ULvUT OY} UO yno & FO YdeISOJOYUG “T “DI 


Am. Jour, Sci.—FourtH Serizs, Vou. XLVI, No. 273.—SrEpremBer, 1918. 
21 


530 Butts—Geologic Section of Blair and 


where a fault is plainly exposed in a cut immediately east 
of the station. The fault plane here dips east at about 

15°, the beds of the overthrust mass being parallel to 
the fault plane and those below the fault being overturned 
with an east dip of 40°. The overthrust mass is Warrior 
limestone and the overridden beds are Carlim limestone. 
This fault is shown in fig. 1. The position of this fault 
or faulted zone is plainly indicated by the sharp bend or 
offset in Canoe Mountain, about 8 miles a little southwest 
of Birmingham and by the fault offsetting Bald Eagle 
Mountain 5 miles northeast of Tyrone. A number of 
other strike faults were discovered showing that this 
region has been faulted in a manner similar to the south- 
ern Appalachian region. 

The classification followed in this paper differs from the 
usual classification in the following particulars: The Loy- 
alhanna limestone is placed in the Mauch Chunk instead 
of in the Pocono, because the author believes that the 
Loyalhanna is probably the same as the Trough Creek 
limestone of I. C. White at the base of the Mauch Chunk 
in the Broad Top Mountain syncline, in Huntingdon 
County. The Burgoon sandstone, which forms the upper 
part of the Pocono, is believed to be of Keokuk or upper 
Fort Payne age, whereas the Loyalhanna is believed to be 
of Warsaw age, a belief founded on the existence of a 
similar cross-bedded limestone of probable Warsaw age, 
in a similar stratigraphic position just above the Fort 
Payne chert at the head of Sequatchie Valley, in eastern 
Tennessee. If the Loyalhanna is thus of Warsaw age it 
should, in the author’s opinion, be classed with the beds 
overlying the Pocono. 

The Pennsylvanian and Mississippian are recognized 
as systems, instead of series in the Carboniferous. 

The Ordovician- Silurian boundary 1s placed at the base 
of the Oswego sandstone, in which the practice of the New 
York State ‘Survey i is followed. It seems reasonable to 
assume that the deposition of this sandstone was the 
result of crustal movements such as are regarded as 
initiating new periods of geologic time. 

The only other important deviation from prevailing 
usage is the recognition of the Canadian and Ozarkian 
systems, in which, of course, the writer follows Ulrich. 
‘The writer is satisfied that there are sufficient grounds 


Huntingdon Counties, Central Pennsylvama. 531 


for this classification but cannot go into the discussion 
of the question now. 


Formation. 


Allegheny 
formation 


Pottsville 
formation 


Mauch Chunk 
shale 


Pocono 
formation 


Catskill 
formation 


Chemung 
formation 


Brallier 
shale 


Description. 
lie 
Shale and sandstone, with workable coal beds. 


Mainly sandstone, clay, and shale, with coal 
locally in middle. 


Mainly lumpy, red shale or mudrock, with 80 
feet of thick-bedded sandstone at bottom to west. 
A little thin sandstone and limestone to east. 
Mostly of Chester age. Siliceous crossbedded 
limestone to west (Loyalhanna limestone) ; 
gray and red, partly argillaceous limestone to 
east (Trough Creek limestone of I. G. White) 
Warsaw age?. 


Thick-bedded, gray sandstone; Burgoon mem- 
ber, at top; shale, red shale, and sandstone 
below. Conglomerate at bottom to east. Thick- 
est to east, in Broad Top Mountain. Most red 
shale to west, on Allegheny front. Osage age. 


Lumpy, red shale or mudrock, thick-bedded, 
micaceous red sandstone. 80 per cent red. Gray 
and greenish shale and gray sandstone with 
marine fossils, 20 per cent. Spirifer disjunctus, 
Camarotoechia contracta, Grammysia elliptica, 
Pteromtes rostratus, and others. 


Mostly shale with thin sandstone layers. Some 
thicker sandstone and conglomerate members. 
Upper 1,000 feet largely purplish or chocolate 
colored to west on Allegheny front, and the 
same with red shale layers in the upper 500 feet 
on Raystown Branch of Juniata River on the 
east. Lower 2,000 feet gray and greenish. 
Chemung fossils common to abundant from bot- 
tom to top. Spirifer disjunctus at very bottom 
on Allegheny front. , 
le 


Fine-grained, siliceous shale in thick, even 
layers revealing their fissility on weathering. 
Largely wavy or dimpled laminae, some even 
and slaty. A few thin fine-grained sandstone 
layers. Fossils small and very scarce. Buchiola 
retrostriata, Probeloceras lutheri, Bactrites aci- 
culus, Phragmostoma natator. Upper Portage. 


532 Butts—Geologic Section of Blair and 


Harrell 
shale 


Hamilton 
formation 


Mareellus 
shale 


Onondaga 
formation 


Ridgely 
sandstone 


Shriver 
limestone 


Helderberg 
limestone 


Tonoloway 
limestone 


Wills Creek 
shale 


McKenzie 
limestone 


Clinton 
formation 


Dove and black fissile (paper) shale. Black at 
bottom to west (Burket member). Black and 
dove interbedded to east. Buchiola retrostriata, 
Paracardium doris, Pterochaema fragilis, Sty- 
liola fissurella, Probeloceras lutherr. Lower 
Portage. 


Hackly shale at top, weathers green; impure 
limestone layers in top 10 to 20 feet. Dark shale 
with thin even sandstone layers in middle to 
west, three thick sandstone members to east. 
Lower one-third dark olive shale grading into 
Marcellus shale below. Chonetes aurora in 
1 foot limestone at very top (Tully?, Upper 
Devonian). Common Hamilton fossils abun- 
dant in hackly shale in upper one-third. Fossils 
searce below. 


Black fissile shale with Letorhynchus lamitaris 
and Styliola fissurella. 


Dark shale with limestone layers. Odontopleura 
aegeria, Anoplotheca acutvplicata and other 
fossils. 


Coarse thick-bedded sandstone. Common Oris- 
kany fossils plenty. Upper Oriskany. 


Thin-bedded siliceous limestone. Dalmamnites 
stemmatus ?, Craterellina robusta, Actinopteria 
textilis, Chonetes hudsomca, and many other 
Oriskany fossils. Lower Oriskany. 


Thick-bedded gray limestones (Keyser, Coey- 
mans, New Scotland). Gypidula prognostica, 
Gypidula coeymanensis, Spirvfer macropleura. 


Thin-bedded limestone. 
alta ?. 


Dove, calcareous, fissile shale, a little limestone. 
Fossils very scarce. Leperditia alta ?. Blooms- 
burg red member, shale, red and green, impure 
limestone and red sandstone—bottom 50 to 
150 feet. 


Limestone and shale; fairly fossiliferous. Kloe- 
denella abundant. 


Fossils few, Leperditia 


Mainly greenish shale weathering purplish. 
Some sandstone. Thin but workable iron ore 
beds. Rather fossiliferous.. Anoplotheca hem- 


ispherica, Beyrichia and many other ostracods. 


Huntingdon Counties, Central Pennsylvama. 533 


Tuscarora 
quartzite 


Juniata 
formation 


Oswego 
sandstone 


Reedsville 
shale 


Trenton 
limestone 


Rodman 
limestone 


Lowville 
limestone 


Carlim 
limestone 


Bellefonte 
dolomite 


Thick-bedded white quartzite. Arthrophycus 
alleghenyensis, (harlani),in upper part. Exten- 
sively used for silica brick. Called ganister. 


Red lumpy shale or mudrock, red and greenish 
eray sandstone. Some finely cross laminated. 
No fossils. 


Medium thick-bedded gray sandstone. Some 
finely cross laminated. No fossils. Bald Eagle 
sandstone of Grabau. Oneida conglomerate of 
Pennsylvania Second Geological Survey. 


hit: 


Thick, dark, rusty weathering, sandstone at top 
with Orthorhyncula linneyt, Byssonichia radiata 
and others. Maysville age. Persistent to Ten- 
nessee. Shale with thin limestone layers in 
upper half. Fissile (shoe peg) shale in lower 
half. Calymene senaria, Dalmanella multisecta, 
Rafinesquina. Black shale at bottom with grap- 
tolites. Eden age. 


Thin-bedded black limestone weathering with a 
eray film on surface. Sparsely fossiliferous. 
Cryptolithus tessellatus = Trinucleus concen- 
tricus, Plectambonites sericea. 


Dark erystalline limestone weathering with a 
rough granulated surface; very characteristic 
and persistent. Fossiliferous. EHchinosphaerites 
zone at top. Upper Black River. 


Dark, thick-bedded, pure limestone, glassy to 
fine-grained. Extensively quarried for flux. 
Streptelasma profundum, Tetradium cellulosum, 
Beatrecia gracils, Inchenaria typa ?. Lower 
Black River. 


Dark, fine-grained limestone, extensively quar- 
ried for flux. Fossils scarce except in Lemont 
argillaceous limestone member. Leperditia fab- 
ulites, Isochitlina amiana, Leptaena incrassata in: 
bottom. Tetradium syringoporoides through- 
out; Lemont member impure, not quarried. 


_Hebertella vulgaris, Rafinesquina champlainen- 


sis, Protorhynca ridleyana ?, Maclurites magna. 


Thick-bedded dolomite yielding much dense 
chert. Fossils scarce. 


534 Butts—Geologic Section of Blaar and 


Axeman 
limestone 


Nittany 
dolomite 


Larke 
dolomite 


Mines 
dolomite 


Gatesburg 
formation 


Warrior 
limestone 


Pleasant Hill 
limestone 


Waynesboro 
formation 


Thin-bedded blue limestone with dolomite lay- 
ers. Fossils. Jvospira strigata, Hormotoma 
artemesia, Hormotoma lmearis, Dalmanella 
wemplet ?, Bolbocephalus seeleyt. 


Thick-bedded, cherty dolomite. Fossils, but not 

abundant. Lecanospira (Ophiletta) compacta, 
Eccyliopterus planibasalis, Eccyliopterus plani- 
dorsalis, Syntrophia lateralis, Cryptozoon steels. 


Thick-bedded, coarse, steely blue dolomite. 
Helicotoma wmangulata, Lingulella?. 


Cherty dolomite, oolitic, yields much oolitic and 
platy scoriaceous chert. Cryptozoon, 2 species, 
common. 


Thick-bedded, steely blue, coarsely crystalline, 
dolomite with many interbedded quartzite layers 
up to 10 feet thick. Surface deeply covered with 
sand and strewn with quartzite bowlders. Con- 
siderable silicified oolite. Ore Hill limestone 
member, thin-bedded, blue limestone; several 
species of trilobites nearest relatives of which 
are in the Hoyt limestone of New York. Stacy 
dolomite member coarse, thick-bedded, steely 
blue, but without quartzite. 


Thick and thin-bedded, blue limestone with thin 
siliceous shaly layers or partings. A few thin 
quartzite layers and an occasional bed of lime- 
stone full of large well-rounded quartz grains. 
Some oolite. Cryptozoon common. Several 
species of trilobites. Muillardia avitas. 


Thick-bedded limestone at top, fossils. Acro- 
cephalites aoris. Argillaceous thin-bedded lime- 
stone at bottom weathering to shale. 


Sandstone, conglomerate, and red and greenish 
shale. 


Huntingdon Counties, Central Pennsylvamia. 535 


ik 


brewood 
sandstone 
Mercer shale. 


PENN. |SYSTEM 


MISSISSIPPIAN 


DEVONIAN 


Z 
= 
Z 
O 
> 
ix} 
= 
te 
to] 
O, 
Qu. 
2) 


536 Butts—Geologic Section of Blair and 


IT. 


Brallier = — = == = == = = ——= L350 
shale a ee 


a 
shee _—<————— 2erket beck shale 


Hamilton 
formation 


Q, 
) 
0 
t 
i) 
) 


Porta 


V, 


meee MIDDLE DEVONIAN 


Tae 
limestone 


al 


Ree 


Clinton. 
formation. 


| Tascarare. | carore. 
qu | Tascarare. | 


S ILU ALAN 
NIAGARA 


a 


formation. Ses aa eens Me OES 


sandstone 


Huntingdon Counties, Central Pennsylvania, 537 


a 


OS Sore tet el ae =; 


E: shale 
et) Ll 
JE 
Q)y§| Trenton limestone FS 320 | 
(¢/83| Hodman limestone === 


O[28| Lowville limestone Fy 


g=| Carlim limestone SS 


Bellefonte 
dolomite 


7 
! 


BEEKMANTOWN 
ee 
ber 


CANADIAN 


A 
‘ 
ch 
: 


a a ee 
i 7 a —sa 
ines dolomite SSS SS eS 


M 
EU RTETSR pee aS RE aa BP Bal 
2 ee er ee eee 
Gatesburg, 5 
formation. 
Pes, DAS ALPES a 


OZARKIAN 


pete) pues ed 


UPPER CAMBRIAN 


CAMBRIAN 


MIDDLE 


CAMBRIAN 
4) 


588 Gooch and Soderman—Barwm and Strontium. 


Arr. XXII—A Method for the Separation and Deter- 
mination of Barwum Associated with Strontium; by 
EK. A. Goocu and M. A. Soperman. 


(Contributions from the Kent Chemical Laboratory of Yale Univ.—eccii.) 


It has been shown by Mar, in a former article from this 
laboratory,’ that barium may be separated quantitatively 
from calcium and magnesium by dissolving the mixed 
chlorides in the least possible amount of water and throw- 
ing the barium out of solution as the hydrous chloride by 
the addition of a 4:1 mixture of concentrated aqueous 
hydrochloric acid and ether, the calcium and magnesium 
remaining in solution. The following account gives the 
outcome of an attempt to adapt this procedure to the 
similar separation of barium from strontium. 

The results of preliminary experiments showed plainly 
that the procedure found by Mar to be satisfactory for 
the separation of barium from calcium and magnesium 
yields high indications for barium when strontium is 
present even in moderate amounts. 

It has been found, however, that excellent results may 
be attained by a modified procedure. The success of the 
operation depends upon so adjusting the amounts of the 
water and of the aqueous hydrochloric acid and ether 


mixture that the barium chloride shall be as insoluble © 


as possible while strontium chloride, in reasonable 
amount, shall be completely dissolved. Without describ- 
ing in detail many experiments with varying amounts of 
the water, acid, and ether used in the process, as well as 
experiments in which alcohol was also introduced (with- 
out beneficial effect), it will be sufficient to indicate the 
procedure by which good analytical separations of 
barium and strontium may be accomplished surely and 
easily. 3 

It has been found that the proportion of water in the 
mixture may be regulated properly by dissolving the 
mixed chlorides in the least possible amount of water 
and adding a suitable amount of a 4:1 mixture of 33% — 
hydrochloric acid and ether. Under such conditions the 
barium chloride is precipitated and strontium chloride 
dissolves. It has been found that the solubility of barium 
chloride after solution in the least possible amount of 

1 This Jour., (3) 43, 521, 1892. 


Gooch and Soderman—Barium and Strontwm. 539 


water and treatment with 50 cm’—75 em? of such a mix- 
ture is practically negligible, while strontium chloride 
equivalent to 0:3 grm. of the anhydrous salt, dissolved in 
the least possible amount of water and treated with the 
mixture, first yields a characteristic precipitate of crys- 
talline needles and then dissolves completely when the 
volume of the precipitating mixture has been sufficiently 
increased and before this has reached the 75 cm? limit. 
The precipitate of barium chloride formed when only 
barium chloride is similarly treated is coarsely granular 
and fails to dissolve upon further addition of the 
precipitant up to the limit named. 

When a solution of barium chloride and strontium 
chloride in the least possible amount of water is similarly 
treated with a considerable volume of the acid-ether 
mixture the former salt is completely precipitated and 
the latter may be partially precipitated at first and, 
excepting any inclusion in the barium chloride, go into 
solution later as the volume of liquid is increased; but 
if the precipitating mixture is added slowly to the ’solu- 
tion of the mixed chlorides, drop by drop for the first few 
cubic centimeters, the liability of the strontium chloride 
to precipitation and inclusion is minimized. 

In the practical application of the method elaborated 
upon these lines, the solution of the mixed chlorides in 
the least possible amount of water may be accomplished 
most easily by adding to the dry salts, contained in a 
beaker, a very little water (beginning with about 0-2 
em® and, if necessary, adding more later), and warming 
gently, with agitation, and then cooling. If crystals 
separate on cooling, the operation is cautiously repeated 
until a cold saturated solution is obtained. 

The precipitation is begun by adding the acid-ether 
mixture to the cold saturated water solution of the mixed 
salts, drop by drop and with constant agitation during 
the addition of the first two or three cubic centimeters of 
the precipitant. Thereafter the precipitant is added in 
amounts necessary to complete the precipitation of the 
barium chloride and dissolve the strontium chloride—50 
-em® to 75 cm? for amounts not exceeding 0-5 grm. of the 
mixed salts nor 0-3 grm. of anhydrous strontium chloride. 
The liquid is decanted upon asbestos in the perforated 
crucible. The residue, washed and transferred to the 
filter with a 4:1 mixture of concentrated hydrochloric 


540 Gooch and Soderman—Barwm and Strontium. 


acid (38%) and ether (applied in a fine jet from a small 
wash bottle), is dried at 150° and weighed as anhydrous 
barium chloride. 

The results of experiments made in the manner 
described upon weighed amounts of hydrous barium 
chloride and anhydrous strontium chloride are given in 
the following table: 


Precipitation by 4:1 Miature of Hydrochloric 
Acid (383%) and Ether. 


Volume 
BaCl..2H.O SrCl. Theory BaCl, of 

taken taken BaCl, found Error _Precipitant 

erm. germ. grm. erm. erm. em? 

A : 
(P9002 ear ies ©2 0-4264 0-4260 —0-0004 50 
050028 Faye, 0-4264 0-4260 —0-0004 50 
O:LOOGA R= 2a 0-0857 0-0855 —0-0002 30 
0:0100) steers se: 0-0082 0-0083 +0-0001 00 
O;0010 eres 0-0008 0-0008 0-0000 50 © 
O20 NOD pes tees 0-0082 0-0082 0-0000 165) 
B 

0-40038 0-0620 0-3412 0-3408 —0-0004 50 
0-3005 0-1200 0-2562 0-2560 —0-0002 50 
0-2001 0-1820 0-1706 0-1705 —0-0001 30 
0-1006 0-2480 0-0858 0-0855 —0-0003 D0 
0-:0503 0-2480 0-0426 0:0428 +0:-0002 50 
0-0010 0-1000 0-0008 0-0008 0-0000 50 
0-1006 0-2480 0-0857 0-0856 —0-0001 15 
0-0100 0-3100 0-0082 0-0084 +0-0002 75 
0-0010 0-3000 0-0008 0-0008 0-0000 19 


These results show that barium and strontium may be 
satisfactorily separated by treating the saturated solu- 
tion of the chlorides with a 4:1 mixture of hydrochloric 
acid of 33% strength and ether, and washing the precip1- 
tate with a 4:1 mixture of concentrated hydrochloric acid 
(38%) and ether, according to the procedure described. 


Chemistry and Physics. 541 


SOLE NTIETE INTELLIGENCE: 


I. CuHemistrRY AND PuHysics. 


1. Modern Inorganic Chemistry; by J. W. Metior. New 
Edition. 8vo, pp. 910. London, 1917 (Longmans, Green and 
Co.).—This is an extensive and unusually excellent text-book. It 
is written in a remarkably clear and interesting manner giving 
many appropriate quotations and allusions. It gives a very 


- gatisfactory account of the facts of inorganic chemistry as well 


as of the generalizations that are derived from the facts, and 
it takes up the most recent theories of physical chemistry in a 
very suitable way. The book indicates remarkably thorough 
knowledge on the part of the author as well as high ability in the 
presentation of the subject. , 

While the book is too extensive and elaborate in its treatment 
of the subject to be put into the hands of beginners as their sole 
text-book, it appears certain that it is a very suitable work for 
the use of all sorts of students of chemistry for reference and 
extra reading, as it should greatly stimulate the interest, and 
extend the knowledge beyond that usually obtained from the 
usual, frequently dry, and often almost childishly brief, text- 
books that are frequently used. 

The book appears to be particularly well adapted for the use 
of teachers of chemistry who wish to put themselves in touch 
with the present developments of the science. The large number 
of examination questions, many of which are taken from actual 
college papers, are also useful, not only for students, but as 
suggestions for teachers. 2S aes Ce 

2. James Woodhouse: A pioneer in chenustry, 1770-1809; 
by Epear F. SmirH. Pp. 296, with portrait, 12mo. Philadel- 
phia, 1918 (The John C. Winston Company ).—This is an inter- 
esting biography of one of the most prominent pioneers of 
American chemistry. Dr. Woodhouse became Professor of Chem- 
istry at the University of Pennsylvania in 1795, just after the 
chair had been offered to and declined by the celebrated Joseph 
Priestley, the discoverer of oxygen, who had recently emigrated 
to the United States. Woodhouse did important work in advo- 
eating and establishing the modern ideas of oxidation which had 
recently been founded by Lavoisier. He had frequent inter- 
course with Priestley and finally entered into a controversy with 
him in connection with the phlogiston theory to which Priestley 
adhered to the end of his days in spite of the great service he 
had rendered in bringing about its overthrow. 

Woodhouse was an ardent laboratory worker, and although 
his scientific results appear to be somewhat trivial from our 
present point of view, his philosophy was sound and his teach- 


549 Scientific Intelligence. 


ing was important. One of his pupils was Benjamin Silliman, 
the founder of this Journal, who spent two periods of study 
with him in 1802 to 1804. Another was Robert Hare, the inven- 
tor of the compound blowpipe. 

Dr. Smith has rendered a valuable service to American chem- 
ical history by publishing this attractive book. H. iL. W. 

3. Laboratory Manual; by ArtHur A. BLANCHARD and 
FRANK B. Wave. Loose-leaf notebook, 95 sheets. New York, 
1917 (American Book Company) .—This manual has been devised 
to accompany “‘‘Foundations of Chemistry’’ by the same 
authors. Each of the sheets is devoted to a single experiment 
or to a series of closely connected ones. In each case the equip- 
ment required and the purpose of the experiment are mentioned, 
then full directions for the work are given, pertinent questions 
in regard to the results are asked, and space is provided for the 
students’ notes. The course of work appears to be very well 
selected and presented for the purposes of beginners in elemen- 
tary laboratory work in chemistry. H. L. W. 

4. Lessons in Astronomy, Revised Edition; by CHarRuEs A. 
Youne. Pp. ix, 420; 118 figures. Boston, 1918 (Ginn & Co.) .— 
This excellent text first appeared in 1891 and it was thoroughly 
revised by its author twelve years later. Accordingly it does 
not seem necessary to give, at the present time, a detailed 
account of the scope and salient features of this. deservedly 
popular book. The preface to the issue of 1918, which is signed 
by Anne Sewell Young, consists of the following single, explana- 
tory sentence: ‘‘ While the greater part of the text remains as it 
was written by its author, such changes have been made in this 
issue as are necessary to bring it down to date.’’ H, Se-Us5 

5. The Origin of our Planetary System; by KucENE MiuEr. 
Pp. 90. Topeka, 1918 (Crane & Co.).—This little book con- 
tains a non-mathematical and supposedly new explanation of the 
genesis and development of the solar system. The author first 
sets forth twelve requirements which must be fulfilled by any 
rational account of the early history of this system and then 
proceeds with the solution of each problem. A few typical 
examples of the facts to be accounted for are: the planets 
revolve around the sun in approximately the same plane, all 
the known planets revolve in the same direction, the planets 
between Jupiter and the sun are relatively small whereas those 
beyond are very large, the planets interior to Jupiter have 
high specifie gravities while the outside planets have low specific 
eravities, ete. | | 

The fundamental hypothesis is that the sun and Jupiter 
originally constituted a double star. Gravitational, centrifugal, 
cohesional, and other forces caused Jupiter to assume an ovoid 
shape with the blunt end turned away from the sun. Tidal 
oscillations and reactional vibrations subsequently forced 


Chemistry and Physics. 543 


Jupiter, when in a fluid state, to throw off pairs of planets; the 
smaller twin being born from the region of greatest curvature 
nearest to the sun, and the larger twin being dropped from the 
most remote region of least curvature. 

‘‘Jupiter’s aphelion distance was decreasing and his peri- 
helion distance was increasing, while his entire orbit was becom- 
ing more and more circular. The first interior planet was 
dropped at a time when Jupiter’s perihelion was very near the 
sun and when his orbit reached the limit of its elongation, and 
he dropped the outermost planet at the same time, but from his 
opposite side. So the first small planet and the first, or outer- 
most, big planet are of the same age.’’ ‘‘Saturn and the 
asteroids are the youngest set of planetary children; Mars and 
Uranus are the next youngest in our system; then come Karth 
and Neptune. This arrangement leaves Venus and Mercury 
unpaired.’’ ‘‘So not only do I assert that the two undiscovered 
planets are there, but I assert without the suggestion of a doubt 
that they MUST BE THERE.”’ 

The author’s style is generally clear and attractive, and he 
presents his case in a very plausible manner. Nevertheless, 
since the deductions are not based on mathematical calculations 
it remains to be seen whether the ‘‘theory’’ will stand the test 
of rigorous, quantitative analysis. tees) Ue 

6. Ozone, and the Ultra-violet Transparency of the Lower 
Atmosphere.—The absorption of ultra-violet light by the atmos- 
phere near the surface of the earth has been recently studied 
experimentally by R. J. Strutt. For distances up to 1200 
yards a spark between cadmium electrodes was used as source. 
For the greatest distance available, namely 4 miles, a quartz 
mercury vapor lamp was employed. The spectrograms were 
taken with a small prismatic camera containing a single 60° 
quartz prism and a quartz lens of 1 inch aperture and 5 inches 
focal length. The source of light was placed behind a quartz 
lens of 3-5 inches diameter in order to focus the radiations on 
the distant station. Under these circumstances, the monochro- 
matic images were round dots instead of the usual spectral lines. 
Lack of an assistant necessitated adjusting the apparatus in the 
daytime and taking the exposures at night. 

“The spectrum of the cadmium spark taken at 3600 feet 
showed no definite indication of ozone, the whole spectrum being 
transmitted to » 2313, right through the region, near » 2536, 
where ozone absorption is a maximum.’’ An exposure of two 
hours, taken on a clear night with the mercury lamp at a distance 
of four miles, recorded the spectrum as far as \ 2536. This 
result may be compared with the limit, \ 2922. of the solar 
spectrum, as obtained by Simony on the Peak of Teneriffe. 
When reduced to standard conditions, the thickness of air 
traversed by the solar light was not greater than 17,900 feet 
whereas the layer of air was not less than 20,100 feet in the 


544 Scientific Intelligence. 


case of the mercury lamp spectrum. It is thus evident that 
the air near the surface of the earth is far more transparent 
than the upper atmosphere to ultra-violet rays, when equal 
masses are considered. Since the more refrangible limit of the 
solar spectrum is known to be due to ozone, it follows that there 
must be much more ozone in the upper air than in the lower. 

By timing the exposures, for long and short distances, so 
as to give about the same photographic density in the green 
and yellow regions of the spectrum, it was found that the 
ultra-violet impressions fell off very rapidly in intensity as 
the thickness of air increased. Strutt gives numerical data and 
computations to show that this rapid decrease in intensity 
cannot be due to the absorption of pure air, but that it may 
be caused by the scattering of light by suspended particles 
having diameters large compared to those of molecules but 
small with respect to the wave-lengths concerned. An alternative 
cause would be a small amount of ozone in the lower atmosphere. 
Spectrograms were accordingly taken by passing the light 
through a tube, 18 mm. long, containing calculable percentages 
of pure ozone. ‘‘We may conclude then that even if the low 
intensity of » 2536 in the long distance spectrum were wholly 
due to ozone absorption, it would be accounted for by less than 
0-27 mm. of ozone in 4 miles of air. We have already seen 
that it is quite probable that an effect equivalent to 0-26 mm. 
ozone is really due to atmospheric scattering. The close agree- 
ment of the two figures is, no doubt, largely accidental, but 
still, allowing for the somewhat uncertain deduction to be made > 
for scattering, it cannot be said that any undoubted effect 
remains to be attributed to ozone absorption. In any case it 
is certain that the ozone cannot exceed 0-27 mm.’’—Proc. Roy. 
Soc., 94 A, 260, 1918. H. S. U. 

7. Molecular Frequency and Molecular Number—The idea 
of ‘‘atomic number’’ has been generalized by H. STANLEY 
ALLEN to apply to chemical compounds. He has introduced 
the term ‘‘molecular number’’ to signify’ the sum of the posi- 
tive charges carried by the atomic nuclei contained in the 
molecule. Thus when a molecule contains @ atoms of an ele- 
ment A, b atoms of B, c atoms of C, so that its chemical formula 
is A,B,C., the molecular number V =aN,+6N,+ cX., where 
N., Nz, NV. are the atomic numbers of the component elements. 
For example, the molecular number of water (H,O) is 10, for 
the nuclear charge of hydrogen is 1, and of oxygen is 8. The 
molecular number generally, but not invariably, comes out even 
due to the circumstance that when the valency is odd the atomic 
number is usually odd also. 

The importance of the new definition lies in the fact that 
certain simple empirical formulae which Allen has shown to 
hold for the atomic numbers and other characteristic constants 


Geology. . 545 


of the chemical elements are equally valid for molecular num- 
bers and compounds. These formulae are Nv = nv, and 
Nv= (x + 4)v,, where N = molecular number, n — small posi- 
tive integer, v — characteristic frequency, andv, = ‘‘frequency 
number’’ = 21x10” sec”. 

Three papers on this subject, by the same author, are devoted 
to testing these relations. The data for a large number of 
organic and inorganic compounds have been used and the equa- 
tions have stood the test in such a great majority of cases as 
to leave little room for the suspicion that the agreement arises 
from an accidental play of numbers. Then, too, the physical 
constants have been derived from many sources and the ealcu- 
lations based on data of different kinds. For a small number 
of compounds the results of low-temperature measurements 
were available and the characteristic frequency was deduced 
from the specific heat. In many cases v was calculated from 

4 -4 

Lindemann’s formula, which is v= 4&7, M V, where 7 = 
absolute temperature of the melting-point, M — molecular 
weight, V = molecular volume, and k= 3-08 X 10!2 (Nernst’s 
value). In still other cases the required frequencies were 
obtained directly from the wave-lengths of the ‘‘residual rays’’ 
isolated by repeated reflections from the surfaces of crystalline 
solids. Allen’s formulae are doubtless expressions of a funda- 
mental property of the solid state of matter, and their form sug- 
gests a probable connection with the quantum theory.—Phil. 
Mag., 35, 338, 404, 445; 1918. Hei Ss) Ue 


Il. Geronoey. 


1. Thirteenth Report of the Director of the State Museum 
and Science Department, State of New York; by JouHn M. 
CLARKE. -Pp. 307, many plates. Albany, 1917.—In this vol- 
ume the present conditions and aspirations of the most extensive 
of the state museums are set forth, and also the present status of 
the various scientific reservations in New York. Among the 
scientific papers are the following: The Philosophy of Geology 
and the Order of the State, by John M. Clarke; Geology and 
public Service, by G. O. Smith; Plastic Deformation of Gren- 
ville Limestone, by D. H. Newland; Geological Features at the 
Champlain Assembly, Cliff Haven, by G. H. Hudson; Some 
structural Features of a fossil embryo Crinoid, by G. H. Hud- 
son; Devonian glass Sponges, by John M. Clarke; Primary and 
secondary Stresses, by John M. Clarke; The Mining and Quarry 
Industry of New York State, by D. H. Newland. 

Still another paper entitled ‘‘Strand and Undertow Markings 
of Upper Devonian Time as Indications of the prevailing Cli- 


Am. Jour. Scit.—FourtaH SERIES, VoL. XLVI, No. 273.—SEPTEMBER, 1918. 


22 


546 - Scientific Intellagence. 


mate,’’ by John M. Clarke, is especially interesting, because in 
these markings the author has further confirmation of his con- 
clusion that ‘‘the late Devonian was a period of cold which 
brought the land ice down to what is now the edge of the sea at 
the northeast [Gaspé], and may well have created conditions, 
regardless of the alternation of the seasons, which would give 
plenty of means for channeling the Devonian strands of New 
York, by the movement of land ice toward the sea, or by the 
landward thrust of the sea ice back from the water.’’ 

R. Ruedemann also has a very important paper, Paleontology 
of arrested Evolution. This is a study of the persistent or con- 
servative genera and chiefly of invertebrates. Of these there are 
506 genera out of a possible total of about 4000, or over 12 per 
cent. Itis among the lower classes of organisms, and again among 
the lower forms within the subclasses, that are found the more 
primitive genera with the greater percentage of persistent forms. 
Restriction and specialization for narrow conditions of life lead 
-““to extinction when these conditions change.’’ On the other 
hand, the animals that live in the open ocean and in the abyss, or 
under subterranean conditions, have more stable environments 
and tend to show a remarkable persistence and immortality. 
Sessile forms also tend toward persistence, and in the marine 
waters persistent types are more common than in fresh waters 
and on the land. Originally the persistent types were the most 
vigorous stocks. ‘‘The evidence here gleaned from the persistent 
types and equally supported by both groups of persistent types, 
the persistent radicals and persistent terminals, leads necessarily 
to the general conclusion that there is no inherent propelling 
force of variation or of development, and that all evolution in the 
last analysis is largely dependent on the exterior agencies sup- 
plied by the ever changing physical conditions.”’ GS. 

2. Geology of the Oregon Cascades; by WARREN Du PRE 
SmitH. Univ. of Oregon Bulletin, n.s., 14, No. 16, 54 pp., 1 pl., 
1917.—The author points out that we know little “‘ with certainty 
about the formations and events prior to the Tertiary,’’ and that 
the West Coast geological events are similar to those on the other 
side of the Pacific. ‘‘The three most striking instances of this 
[similarity] are the period of Tertiary gold deposition, prac- 
tically contemporaneous around the entire Pacific arc, the Hocene 
coal formations, and the tremendous eruptions of basaltic and 
andesitic lavas, which continue to this day, though not on so 
extensive a seale as in the past. 

‘‘The general conclusion is that the geology of the various 
countries bordering on the Pacific must be deciphered and inter- 
preted by duly considering the data from all these regions.’’ 

Osis 

3. The Evolution of Vertebre, and The Osteology of some 

American Permian Vertebrates. III; by SaAmMuEL W. WILLIS- 


Geology. 547 


TON. Contrib. from Walker Museum, 2, No. 4, pp. 75-112, pls. 3, 
4, text figs. 1-19, 1918.—The first paper, as the title indicates, 
treats of the evolution of the vertebrx, and upholds the concep- 
tion first worked out by Cope. The Stegocephalia in the Temnos- 
pondyli have divided vertebra, inherited from the fishes. Out of 
this stock with embolomerous vertebre arose the reptiles in the 
late Paleozoic. The succeeding changes are then traced through 
the various orders of reptiles. 

In the second paper, the author discusses the skulls and other 
parts of the skeleton of Hryops, Chenoprosopus, Naosaurus, 
Sphenacodon, and the new genus Platyops. Both papers are 
fully illustrated by excellent drawings made by the author. 

CUS: 

4. Onaping Map-area; by W. H. Couuins. Geol. Survey 
Canada, Mem. 95, 157 pp., 11 pls., 8 text figs., 2 maps, 1917.—In 
this memoir are clearly described the pre-Cambrian rocks of the 
Onaping area lying to the north of Georgian Bay and Sudbury, 
and their economic content. The geologic succession is as fol- 
lows: Pleistocene thin glacial deposits; great unconformity ; 
Huronian division, separated into the upper basic intrusives 
(= ?Keweenawan) and the lower Cobalt series; great uncon- 
formity; pre-Huronian highly metamorphosed division, which 
includes the younger granite-eneiss bathyliths, and below, the 
great schist complex. Collins prefers for the present to use the 
term pre-Huronian rather than Keewatin, Laurentian, or Algo- 
man. This because ‘‘no reliable classification of the pre-Huron- 
ian can be made until a correlation datum plane has been 
established within the pre-Huronian”’ area. Cz.8: 

5. Timiskaming County, Quebec; by M. E. Witson. Geol. 
Survey Canada, Mem. 103, 197 pp., 16 pls., 6 text figs., 1 map, 
1918.—This is an interesting report describing the pre-Paleozoic 
formations or the basal complex, the physiography, and the 
economic geology of the area, along with a presentation of its 
special problems. The interesting Huronian tillites are also 
described, and the small area of Paleozoic strata is believed to 
be a down-faulted mass into the basal complex, or more specifi- 
eally, into the Abitibi group. The Keweenawan, or Nipissing 
diabase, is referred with doubt to the pre-Cambrian, and 
the Huronian (Coba!t series) and the Basal Complex definitely. 
The latter includes the pre-Huronian bathyliths, the Abitibi 
group and the Grenville series. CaS. 

6. The Piiocene History of northern and central Mississippi; 
by Eucene W. SHaw. U.S. Geol. Survey, Prof. Paper 108-H, 
pp. 125-163, pls. 45-60, text figs. 21-25, 1918——This good work is 
of especial interest in pointing out that the long misinterpreted 
Lafayette formation is not a depositional unit, and that most of it 
is weathered material belonging to various underlying formations. 
In the opinion of Mr. Shaw, ‘‘the material called ‘Lafayette 


548 . Scientific Intellagence. 


formation’ in Mississippi is the product neither of Pleistocene 
icy floods from the north nor of a marine invasion. it is not a 
Pliocene blanket of waste from the Appalachians gradually 
spread over the State by streams; and it does not consist alto- 
gether of parts of pre-Phocene formations, with their surface 
residuum. It is-believed to be made up of unrelated or dis- 
tantly related materiais that have been erroneously grouped 
together and to consist in the main of more or less modified parts 
of the underlying formations, including some residuum and 
colluvium, and of terrace deposits of Pliocene and Quater- 
nary age.’’ CoS 


Ill. Misce,LAnerous Screntiric IN? ELLIGENCE. 


1. Chemistry of Food and Nutrition; by Henry C. SHER- 
MAN, Ph.D. Second Edition. Pp. xiv, 454. New York, 1918 
(The Macmillan Co.).—With the science of nutrition bringing 
new and epoch-making contributions at exceedingly short inter- 
vals in the past few years it is difficult, if not impossible, to find 
any dependable account of the newer results at a time when we 
begin to realize that ‘‘food will win the war.’’ Doubly difficult 
is the task set for anyone who ventures to present the story of 
food and metabolism in its newest and changing aspects. The 
comparison of the two editions of Professor Sherman’s book 
shows how much has needed to be expressed anew within a few 
years. The changes are, perhaps, less conspicuous in the inter- 
pretation of intermediary metabolism and the energy problems 
than in the discussion of the protein factor, the novel features 
of the little understood vitamines and the so-ealled ‘‘balancing’’ 
of the diet. The revision is both timely and well done. There 
is an historical perspective, a balancing of evidence and a sane 
judgment on many debated topics. The new edition will be 
quite as helpful as was the earlier one. Te By: 

2. The Physical Chemistry of the Proteins; by T. BRAILSFORD 
Ropertson. Pp. xv, 483.. New York, 1918 (Longmans, Green - 
& Co.).—In the early periods of the modern popularity of colloid 
chemistry the tendency was to treat all of the representative 
substances that belong in this domain in a uniform fashion and 
to attempt to make their phenomena conform to relations 
observed to hold for some special group. Robertson quite 
properly insists that the colloids represent an exceedingly 
heterogeneous group—hence the justification for imdependent 
consideration of the illustrative type seen in the proteins. 
This volume is a new edition of the author’s ‘‘Die physikalische 
Chemie der Proteine,’’ published in 1912. It deals extensively 
with the descriptive chemistry of the proteins, in so far as this 


Miscellaneous Intelligence. 549 


knowledge is indispensable for a fundamental conception of the 
physico-chemical phenomena. The content of the subject-mat- 
ter is indicated by the major subdivisions of the text, viz.: 
Chemical Statics in Protein Systems; The Electrochemistry of 
the Proteins; The Physical Properties of Protein Systems; 
Chemical Dynamics in Protein Systems. iL. Be Mi 
3. Lecithin and Allied Substances; The Lipins; by Hucu 
Macutean. Pp. vu, 206. London, 1918 (Longmans, Green and 
Co.).—The ‘‘lipins’’ are defined by the author as substances of a 
fat-like nature yielding on hydrolysis fatty acids or derivatives 
of fatty acids and containing in their molecule either nitrogen, 
or nitrogen and phosphorus. This is not the sense in which the 
term has been employed by some American writers; but at 
any rate the author’s intent is clear. Any attempt to bring 
order out of chaos, such as the literature of lecithin and allied 
’ subjects represents, is a desideratum; and when it is undertaken 
by one, like Maclean, who is experienced in this field, the effort 
is doubly weleomed. The volume is representative of the now 
well-known Monographs on Biochemistry. That it does not 
overlook ‘‘ancient history’’ is attested by the long chapter on 
that much debated subject, protagon, for which it might serve 
as a funeral oration. L. B. M. 
4. Dvurections for a Practical Course mv Chemical Physiology. 
Third edition; by W. Cramer. Pp. vii, 119. London, 1917 
(Longmans, Green and Co.).—The author states that ‘‘the 
arrangement of the work differs from that generally followed, 
in that the student is at the outset provided with substances 
familiar to him, such as a potato, an egg, lard, butter, ete... . 
In this way he is introduced to the subject without interposing 
complex chemical conceptions, which the usual arrangement of 
dividing the subject into the study of carbohydrates, fats, and 
proteins necessarily involves.’’ Many teachers of the subject 
will probably debate the alleged superiority of this scheme. 
There is nothing essentially novel in the little manual, though it 
has the advantage of inexpensive form. Numerous omissions 
may doubtless be accounted for on the basis of the comparatively 
elementary character of the course intended to be served. 
L. B. M. 
5. An Outline of the History of Phytopathology ; by HERBERT 
Hick WHETzEL. Pp. 130. Philadelphia 1918 (W. B. Saunders 
Co.).—Professor Whetzel has made a valuable contribution to 
the literature of historical biology. From the earliest mention of 
plant diseases, he traces the development of our knowledge and 
control of them down to recent progress in this country. Stress 
is laid on the most significant discoveries and the more important 
individuals. that have contributed to the advancement of the 
science. In the opinion of the author, Anton de Bary should not 
be considered the father of modern plant pathology; this title is 


550 Scientific Intelligence. 


conferred upon Julius Kuhn. The characterizations of prom- 
inent men are terse but well done and there are many very good 
portraits. The value of the book, which is strictly an outline, is 
further enhanced by a classified bibhography and an index. 

Hi Dr Hyde 


OBITUARY. 


ProFressor HeNry SHALER WiuuiAMs of Ithaca, N. Y., well 
known for his valuable work in geology and paleontology, died 
in Havana, Cuba, on July 31 at the age of seventy-one years. He 
was born at Ithaca on March 6, 1847, was graduated at Yale 
university with the degree of Ph.B. in 1868, and remained as 


assistant in paleontology from 1868 to 1870; in 1871 he received 


the degree of Ph.D. His first position as a teacher was as pro- 
fessor of natural science at Kentucky University in. 1871-72; 
from there he went to Cornell University as professor of geology, 
remaining at Ithaca until in 1892 he became Silliman professor 
of geology at Yale. In 1904 he returned to Cornell as head of 
the department of geology, which position he held until he 
became emeritus in 1912. Much of his time has been spent dur- 
ing recent years in Cuba, in part in the investigation of oil 
fields. Huis contributions to science, and particularly to paleon- 
tology on its broader side, were numerous and important; this 
subject will be presented more fully in a later number. As an 
associate editor of this Journal his work was of great value, 
especially for the years following his appointment until he left 
New Haven in 1904; for a year, beginning 1893, he performed 
the duties of editor-in-chief with the unselfish devotion charac- 
teristic of the man. He was a member of several prominent 
geeological societies and through the kindliness of his nature won 
for himself a wide circle of friends. 

PROFESSOR JOHN Durer Irvine, who had since 1907 held the 
chair of economic geology in the Sheffield  1entifie School of 
Yale University, died of pneumonia in July while serving his 
country as instructor in an engineering camp in Franee. He 
was in his forty-fourth year and had already made a wide repu- 
tation in his own department, particularly with reference to the 
subject of ore deposits. For a number of years he had been 
editor of the journal ‘‘ Economie Geology.’’ His loss is a serious 
one to the science of the country, as to the university with which 
he was connected. 

CHARLES CHRISTOPHER TROWBRIDGE, assistant professor of 
physies in Columbia University, died suddenly on June 2 in his 
forty-ninth year. He had been connected with the teaching staff 
of Columbia since 1892 and was especially known for. his work in 
ornithology. An important paper by him on ‘‘The Interlocking 
of Emarginate Primary Feathers in Flight’’ was published in 
this Journal for February, 1906 (vol. 21, pp. 145-169). 


THE 3 ee feat 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


Sanna 


Art. XXIII.—The Green Rwer Desert Section, Utah;* 
by Wirson B. Emery. 


GENERAL STATEMENT. 


The charm of the Southwest and of its geology ever 
lingers with me, and so it was with considerable pleasure 
that in 1917 I again undertook work in this region for the 
U.S. Geological Survey, after several seasons spent else- 
where. The examination in hand, which was a recon- 
naissance to determine the oil possibilities of the Green 
River Desert, Utah, necessitated a more or less detailed 
study of the stratigraphy of the area, and it is the results 
of this phase of the investigation that I shall present in 
the following pages. These results constitute further 
evidence of the remarkable similarity in hthologic char- 
acter and stratigraphic sequence of the thick series of 
sedimentary beds exposed broadly over the vast area 
of the Colorado Plateaus. Very frequent comparison 
will be made with the rocks of the Navajo Country in the 
southern Colorado Plateaus, for it 1s with the stratig- 
raphy of this region, embracing many hundred square 
miles in southern Utah, northern Arizona, and north- 
western New Mexico, that I have first-hand knowledge, 
acquired during a long field season in 1913, while assist- 
ant to Professor Herbert EK. Gregory, in his studies there 
for the United States Geological Survey. 

Green River Desert is situated in east-central Utah 
and embraces that portion of the Colorado Plateaus 
which is in Emery and Wayne counties, between the Den- 

* Published by permission of the Director, U. S. Geol. Survey. 


Am. Jour. Sct.—Fourta Series, Vou. XLVI, No. 274.—Octosrr, 1918. 
23 


552. Hmery—Green Rwer Desert Section, Utah. 


ver and Rio Grande Railroad, Dirty Devil River, San 
Rafael Reef, and the canyon of Green River (fig. 1). 
The rocks exposed in the Desert range in age from Penn- 


Paes 


\ 
\ Provo 
72 


"Richfield 


Marysvale 
€ re 


INDEX MAP 


sylvanian (?) to Upper Cretaceous and embrace a thick 
series of sandstones with some shale and a very little 
hmestone. The oldest bed examined was a white sand- 
stone of Pennsylvanian (?) age which is extremely cross- 
bedded and is saturated with petroleum. Above it lies, 
probably unconformably, the Moenkopi formation (heré 


Emery—Green River Desert Section, Utah. 558 


assigned to the Lower Triassic), constituted principally 
of red-brown sandstone and shale, but containing at its 
base a prominent zone of buff shale and sandstone. The 
Moenkopi is unconformably overlain by the Shinarump 
conglomerate (Triassic), which is a very valuable key 
formation for correlation purposes, because of its pecu- 
har lithologic character and widespread distribution. 
The variegated shales of the Chinle formation (Triassic) 
which lie perhaps unconformably above the Shinarump, 
are succeeded, also perhaps unconformably, by the mas- 
sive, much cross-bedded sandstones of the Wingate 
(Jurassic). There is some evidence to indicate that 
the overlying beds, here tentatively correlated with the 
Todilto formation (Jurassic), rest unconformably on the 
Wingate. The Todilto (?) in addition to a rather hetero- 
geneous mass of reddish shale and dirty gypsum, con- 
tains near its base a dense limestone which is fossil- 
iferous and is therefore an invaluable key bed, as it occurs 
in the midst of a considerable thickness of unfossiliferous 
strata. The Navajo sandstone (Jurassic) succeeds the 
Todilto (?) and is composed of massive red sandstone at 
the base, with thinner-bedded red sandstone and sandy 
shale above and a prominent thick belt of gypsum at the 
top. The Wingate, Todilto (?), and Navajo together 
form what has been called the La Plata groups of rocks. 
The MceElmo formation (Cretaceous?) comes next above 
- the Navajo and consists of coarse white sandstone and 
conglomerate at the base (the Salt Wash sandstone mem- 
ber), variegated shales containing dinosaur bones and 
well polished pebbles resembling gastroliths in the mid- 
dle portion, and at the top, coarse sandstones and con- 
glomerates with minor quantities of variegated shale. 
The McElmo is believed to rest unconformably on the 
Navajo. An unconformity occurs also at the top of the 
McElmo, for it is in places overlain by a thin bed of 
Dakota sandstone (Upper Cretaceous) but is elsewhere 
in contact with the Mancos shale (Upper Cretaceous). 
This shale, which is several thousand feet thick, is blue- 
eray to drab in color and fossiliferous at numerous hori- 
zons. Itis an important stratigraphic marker because of 
‘its hthologic character and fossil content. 

The areal distribution of these formations in the 
Green River Desert is shown in the geologic sketch map 


Emery—Green River Desert Section, Utah. 


bo4 


HIG. 12; 


GEOLOGIC 
OK ETLGH. MAP 


OF 
GREEN RIVER DESERT > 
7 UTAH 


Geology by 
Wilson B Emery 


Base from San Rafael Quadrangle 


U.S.Geol Survey 


Seale 1 inch = about 91% miles. 


2. 


iG: 


Emery—Green River Desert Section, Utah. 555 


(fig. 2), and their correlation with beds 1 in adjacent areas 
is Shown in the table on page 556. 


PENNSYLVANIAN (?) SANDSTONE. 


A sandstone of Pennsylvanian(?) age which is exposed 
in Klaterite Basin and also outcrops rather broadly in 
San Rafael Swell behind ‘‘The Reef,’’ is the lowest 
formation I had the opportunity of seeing in the Green 
River Desert. It is heavily impregnated with oil on the 
outcrop and is probably oil-bearing throughout its areal 
extent in this region. 

This sandstone, which is composed mostly of translu- 
cent quartz grains held together by calcareous cement, is 
coarse-grained, massive, very cross-bedded, and rather 
soft. Where not impregnated with petroleum it is white 
both on the fresh face and on weathered surfaces, but 
where filled with oil is a steel gray at the surface but dark 
brown to black on fresh fracture. It commonly weathers 
into deep pockets, constituting excellent rain water res- 
ervoirs, and is further characterized in San Rafael Swell 
by searlet spots and blotches on the weathered surfaces. 

Near Temple Mountain, San Rafael Swell, fully 100 
feet, and in Elaterite Basin about 50 feet of the Pennsyl- 
vanian (?) sandstone are exposed. In both localities the 
sand is heavily saturated with oil from top to bottom, but 
the oil is definitely confined to certain, probably more 
porous layers, for I saw no sign of oil in clean white 
laminae in direct contact with dark petroliferous laminae. 

At the top of the Pennsylvanian (?) near Temple 
Mountain is a very distinctive bed containing quartzite 
pebbles and irregular areas of calcite and having the 
appearance of a coarse, irregular conglomerate. It 
attains a maximum thickness of 7 feet, but is locally 
absent, which with its conglomeratic character is indica- 
tive of an unconformity at this horizon. The presence of 
an unconformity at the top of the Pennsylvanian (?) is 


= LEGEND (Fie. 2). 
TRIASSIC JURASSIC CRET? CRET. 
—_ Ba ie] SS Ema 
=) 6s hl S eS 
piarop Chinle eee 5s. Todilto form. ae ss. M°Flmo Mancos shale 


congl. OL eer aS LOrI.. and Dakota ss; 
7 La Hlata Greup where present 


556 = Hmery—Green River Desert Section, Utah. 


Table able of Correlations. 


Green oy 
ae G er 
ge | tomaye coutey af Navajo Country a/ [Henry Mountains Pee etre Oe ae Cisen:stiver: Besaht aint see ete fete gh 


2 

= Mancos shale Manceos shale 
Oh 

o 0 

8 po?) 

© 5 

bv Dakota sandstone Dakota sandstones akota sandstone 


Unconformity ‘Unconfomnity Unconfommity - 


Neklmo formation 
Salt Fash sand-~ 
stone mexber 


Unconformity 


McElmo formation Salt Yash 


sandstone meambs 


Flaming Gorge 
group 


Dnconfomity7 


Navajo sandstone 
Unconformity? 
Todilto (2) 
fommation 
Unconf ormity? 


Navaio sandstona 


McElmo formation 


Todilto 
formation: 


Jurassic 


La Plata group 


Vermilion Cliff 
group 


La Plata group 


Winsate La Plata sandstone 
sandstone 


Unconformity? 


Wingate 
sandstone 
Unconformity? 


Chinile formation "a" division | Chinle formation 


Uncenfemmity? Unconformity? 
Shinarump Shinaruzp Shinarump 
conglomerate conglomsreta conglomerate 
Unconformity. Unconformity 


Triassic 


DeChelly sandstone o" division Absent 


Nooenkopi formation 


Moenkopi formation 


Unconformity Unconfornity? 


Undifferentiated 
Pennsylvanian 


Pennsylvanian (7) 


(= 1) Gregory, H. E., Geology of the Navajo country, U. S. Geol. 
Survey, Prof. Paper 93, pp. 15-16, 1917. 
b (= 2) Gilbert, G. K., Report on the geology of the Henry Mountains, 
U. S. Geog. and Geol. Survey of the Rocky Mountain region, p. 6, 1877. 
¢ (= 3) Lupton, C. T., Oil and gas near Green River, Grand County, ” 
Utah, U. 8. Geol. Survey, Bull. 541, p. 124, 1914. 


Emery—Green River Desert Section, Utah. 557 


also suggested by the apparent absence of the white, 
petroliferous sandstone described above in a number of 
places toward the junction of the Grand and Green 
rivers, for though I did not have the opportunity of 
examining this area in detail, from a distance it appears 
that this oil sand is locally absent. 

The sandstone just described underlies the beds re- 
ferred by Gilbert to the lower member of what he 
termed the Shinarump group in the Henry Mountains 
region* and which is now known as the Moenkopi forma- 
tion in the Navajo Country to the south.® In the north- 
ern part of that area the beds directly below the Moen- 
kopi are known as the Goodridge formation, and from the 
physical character and sequence it appears likely that 
this white Pennsylvanian (?) sandstone is equivalent to 
the top of the Goodridge. The fact that the Pennsylva- 
nian (?) sandstone is oil-bearing in Green River Desert 
as is the Goodridge near Bluff on the San Juan River in 
southern Utah, affords further evidence of the validity of 
such a correlation. The Goodridge formation in the San 
Juan field was definitely determined to be Pennsylvanian 
in age on the basis of fossils collected there by Woodruft.® 
A brief examination in the Green River Desert revealed 
no fossils in the white sandstone, but because of its strat- 
igraphie position it is here provisionally referred to the 
Pennsylvanian. 


MoENKorPiI FoRMATION (TRIASSIC). 


The Moenkopi formation here includes the series of 
reddish shales and sandstones between the white Penn- 
sylvanian (?) sandstone below and the Shinarump con- 
glomerate above, the intervening De Chelly sandstone not 
being present in this area. The Moenkopi is exposed in 
the heart of San Rafael Swell and under The Ledge 
between the Dirty Devil and Green rivers, where it forms 
the ‘‘riser’’ to the ‘‘step’’ made by the overlying Shina- 
rump conglomerate. 

The Moenkopi formation is arenaceous throughout. At 

* Gilbert, G. K., Geology of the Henry Mountains, U. 8. Geog. and Geol. 
Survey of the Terr., p. 6, 1877. 

°*Gregory, H. E., Geology of the Navajo country, U. S. Geol. Survey, 
Prot. Paper 93; ©. LLL 1917; 


® Woodruff, H. G., Geology of the San Juan oil field, Utah, U. S. Geol. 
Survey, Bull. 471, p. 85, 1912. 


558 Hmery—Green Rwer Desert Section, Utah. 


the base are 60 to 75 feet of white to brownish buff sandy 
shale with numerous interbedded thin sandstones of the 
same color. This part of the formation makes a rather 
conspicuous feature of the landscape, for it is in sharp 
contrast to the nearly dead white color of the underlying 
Pennsylvanian (?) sandstone and to the alternating red 
sandstones and shales of the upper Moenkopi. The sand- 
stone in the Moenkopi consists of fairly well-rounded 
small quartz grains, held together by a calcareous cement. 
The finer, more thinly bedded sandstones are beautifully 
ripple-marked. 

About 140 feet above the base of the section near Tem-- 
ple Mountain is a thin layer of very calcareous buff sand- 
stone, with a coquina-like appearance, containing many 
fossil fragments. A hurried examination revealed no 
identifiable specimens, but Mr. Walt M. Small, consulting 
ceologist, of Tulsa, Oklahoma, who was with me when I 
visited this section, informs me that he later obtained 
collections from this horizon on the west side of the Swell. 

The character of the Moenkopi is shown in the follow- 
ing detailed sections: 


Section of Moenkopi formation, North Temple Wash, T mile + 
north of Temple Mountain, San Rafael Swell, Utah. 


(Measured with the assistance of Milton Anderson and Walt M. Small of 
Tulsa, Okla.) 


Unconformity 
1. Sandstone, reddish brown, medium grained with 
some purple shale “at: top “for oon eee 128’ 


2. Sandstone and shale, buff to ecru. Contains a lens- 

ing oil sand 4’ thick from 30’ to 40’ above base 117’ 
3. Sandstone, red-brown, medium grained, thin to mas- 

sive bedded, cross-bedded, ripple-marked, contains 

some “shale i202. iss eek. see he 193’ 
4. Sandstone, weathers steel gray, darker gray-brown 

on fresh fracture, lenticular, saturated with 


DetOleuIM =.=. Ju. Se eae eae oo ee a0. 
5. Sandstone, buff to ecru, very limy; contains broken 

fossils: weathered surface resembles .coquina... 4’ 
6. Sandstone and shale, buff, thin-bedded .......... wie SOL 
(.. Shale, very sandy, waite <2 oa 6 2 he ee ey 
Uneconformity 


583-586’ 


Emery—Green River Desert Section, Utah. 559 


Section of Moenkopi formation near Elaterite Spring, Elaterite 
Basin, Utah. 
1. Conglomerate and coarse light sandstone. Shi- 
narump conglomerate. 


Unconformity 
2. Sandstone with shale becoming more prominent 


toward top; red-brown, upper two-thirds almost 
all shale. One foot of leached greenish shale and 


SMOLIN LOIES cree. idk std Ba cab ce Sil es 102’ 
Sandstone, buff, weathers red-brown, fine-grained, 
massive—a single bed, prominent ledge maker .. atte 


4. Shale, sandy, red-brown, chocolate, and cream-col- 
ored toward top with considerable red-brown 


sandstone in thin layers, ripple-marked ........ 62’ 
5. Sandstone, red-brown, weathering to flakes; thicker 

meadere than that, DelOW* =. ac 0... ccs b ee cee ee 3! 
6. Sandstone, red-brown, ripple-marked, fine-grained, 

with interbedded red-brown shale ............. 24’ 


7. Sandstone, red-brown, fine-grained, honey-comb 
weathering in places. Ledge maker. Lower 4’ 
a single bedded. Thinner bedded above ........ oy 
8. Shale, red-brown, sandy, with some minor cream- 
colored, sandy shale and with numerous inter- 
bedded, thin-bedded sandstone—red-brown, me- 
dium to fine-grained, much _ ripple-marked. 
PareMGNS £60 AKC 1 seo aie he cna vies < es ee a we 78’ 
9. Sandstone, thin-bedded to beds 3’ thick, brown, 
weathering light brown to buff, with interbedded 


Seale take ClO); > Wedge maker ey ri. oe. Eos 16’ 
10. Shale, sandy, with some thin sandstone; cream col- 
DESC ge as Sat Se Poe Ge ae ES Aaa eee ae 45’ 


11. Sandstone, white, coarse-grained, impregnated with 
petroleum. Pennsylvanian(?) sandstone. 


356’ 


The beds just described are limited both above and 
below by unconformities. They constitute the (c) divi- 
sion or lowest member of Gilbert’s Shinarump group in 
the Henry Mountains region, which together with a thick 
series of overlying beds were referred provisionally to 
the Jura-Trias by him. Though these beds have not been 
actually traced into the Moenkopi formation of the Nav- 
ajo Reservation, I think the correlation is amply war- 
ranted on the ground of position in the sequence, for they 
underlie the Shinarump conglomerate, which is an excel- 


560 HEmery—Green Rwer Desert Section, Utah. 


lent distinctive horizon that Gregory’ has shown is 
equivalent in northeastern Arizona with the similar bed 
in the Henry Mountains, and overlie beds of probable 
Pennsylvanian age. The equivalence is further empha- 
sized by likeness in lithology, every lithologic feature of 
the series in the Green River Desert being, I believe, 
susceptible of duplication on the Navajo Reservation. 
The De Chelly sandstone, present in places between the 
Moenkopi and Shinarump on the Reservation, is Bias 
in Green River Resert. 

The brief examination of the Moenkopi formation on 
the borders of Green River Desert did not result in the 
collection of identifiable fossil forms, though a limy bed 
containing shell fragments was noted in the lower part 
of the formation near Temple Mountain. Butler has, 
however, collected fossils on Miners Mountain near 
Fruita, about 45 miles southwest of Temple Mountain, 
from a limestone about 300 feet below the Shinarump 
conglomerate, which Girty has determined to be Triassic 
(probably to be correlated with the Lower Triassic, 
Thaynes and Woodside formations of the Wasatch 
range). This fossiliferous limestone is interbedded in 
a series of reddish sandstones and shale, which, because 
of lithology and stratigraphic position, I believe cor- 
relative with the Moenkopi of the Green River Desert. 
The Moenkopi is accordingly here referred to the Trias- 
sic, though the Moenkopi of the Navajo Reservation was 
referred by Gregory to the Permian (?), because in that 
area the various bits of fossil evidence obtained were 
contradictory.® 


SHINARUMP CONGLOMERATE (TRIASSIC). 


The Shinarump conglomerate, which unconformably 
overlies the Moenkopi formation, is more resistant to 
erosion than are the beds above and below, and where 
inclined at low angles as it is under The Ledge, makes 
a prominent bench in the topography. In San Rafael 
Swell it is sharply upturned and forms a small ‘‘hog- 
back.’’ 

The Shinarump, from 80 to 100 feet thick, is generally 

“Gregory, H. E., op. cit. 

§’ Butler, B. S., Ore deposits of Utah, U. S. Geol. Survey, Prof. Paper 


111, in press. 
°Gregory, H. E., op. cit., pp. 30-31. 


Emery—Green River Desert Section, Utah. 561 


hght-colored, having a somewhat Nile-greenish tinge on 
exposed faces, though locally it weathers almost black. 
It is composed of very coarse-textured, cross-bedded and 
massive sandstone and conglomerate. The conglomerate 
is of two types, the one consisting of water-worn black 
and brown quartz pebbles one-eighth to one-fourth of an 
inch or more in diameter, the other of angular yellow and 
drab lmestone and shale pebbles. Limestone pebbles 
appear to be absent under The Ledge, but are distributed 
from top to bottom of the formation near Temple Moun- 
tain and are especially prominent at the top. <A diagnos- 
tic feature is the abundance of fossil wood, some of it of 
large size, as for example, a single trunk on Black Mesa 
near West Pass, Klaterite Basin, which measures 15 feet. 
in length by 1 foot in diameter. The Shinarump is in 
places saturated: with petroleum. In the Temple Moun- 
tain region, it is the source of the radium-bearing ores 
which occur in pockets associated with fossil wood. The 
Temple Mountain mine is the type locality of uvanite, a 
new vanadium-bearing mineral described by Hess and 
Schaller.?° 

The beds just described unconformably overle the 
Moenkopi and constitute the ‘‘b’’ division or middle con- 
glomerate member of Gilbert’s Shinarump group in the 
Henry Mountain region and the Shinarump conglomer- 
ate of other authors in the Colorado Plateaus. The 
Shinarump is a most valuable marker, for its very distinct 
characteristics with their remarkable similarity over a 
wide area render it an unmistakable key-bed for correla- 
tion purposes. No fossils were observed in the Shina- 
rump in Green River Desert, and their exceeding rarity 
in other places makes determination of the age of the 
formation difficult. It has, however, been tentatively 
regarded by Gregory" as probably of Upper Triassic 
age on the basis of stratigraphic position and on such 
meager fossil collections as have been made, and this 
determination is accepted here. 


CHINLE ForMATION (TRIASSIC). 


The Chinle formation embraces the variegated shales 
and red sandstones between the Shinarump conglomerate 
Hess, F. L., and Schaller, W. S., Pintadoite and Uvanite, two new 
vanadium-bearing minerals from Utah, Jour. Wash. Acad. Sci., 4, p. 578, 


1914. 
"Gregory, H. E., op. cit. 


562 Hmery—Green River Desert Section, Utah. 


and the massive Wingate sandstone. It is exposed in 
The Ledge and upstream in the canyon of Green River to 
within a few miles of the mouth of the San Rafael and 
comes to the surface again back of San Rafael Reef. 
Where the beds are inclined at low angles the Chinle 
weathers back to a steep slope underlying the vertical 
cliff of the massive lower portion of the La Plata group, 
a where not capped by La Plata weathers into badland 
orms. 

Shale predominates in the lower part of the Chinle 
formation but gives way to sandstone above. The shale 
is very argillaceous, rather firmly cemented, hard, friable, 
and of variegated colors, including heliotrope, lavender, 
mauve, turquoise, dove, cream, and white, and with it are 
interbedded thin sandstones similar to those constituting 
the upper part of the formation. The shale rather grad- 
ually loses its ‘‘marl’’-like character becoming more and 
more sandy until finally in the upper part of the forma- 
tion the beds are sandstone rather than shale. This 
sandstone is fine-grained, massive, cross-bedded, and in 
the San Rafael Swell region its color is maroon with a 
terra-cotta cast, but under The Ledge the color partakes 
more of an orange-terra-cotta, the maroon tinge being 
absent. 

In the section measured in Elaterite Basin a limestone 
conglomerate such as occurs in this formation in the Nav- 
ajo country, where it is a diagnostic feature, is present 
in the Chinle about 35 feet above its base. Near Temple 
Mountain, however, the Chinle consists entirely of sand- 
stone and shale, but limestone conglomerate like that 
which elsewhere occurs in the body of the formation is 
present at the base. 

A-detailed section of the Chinle was not measured in 
Temple Wash, near Temple Mountain, San Rafael Swell, 
but its thickness was determined as 210 feet. In this 
locality approximately the lower one-half of the section 
is composed of variegated, heliotrope, lavender, mauve, 
and red-brown argillaceous shale containing thin beds 
of sandstone, while the upper part is composed princi- 
pally of sandstone which is medium- grained, much cross- 
bedded, lenticular and terra-cotta maroon in color. A 
detailed section of the Chinle rocks measured along the 
trail over The Ledge between French Spring and Elater- 
ite Spring follows: 


Emery—Green River Desert Section, Utah. 563 


Section of Chinle formation m The Ledge along trail from 
French Spring to Elaterite Spring. 
1. Sandstone, red-brown, massive, cross-bedded—Win- 
gate sandstone. 
2. Shale, very sandy, becoming increasingly so toward - 
top; red-brown in color; grades into overlying 


«ER CON CEM TE TVS Sa 01d OMIA Se aa ote 150’ 
3. Shale, hard, friable, variegated lavender, heliotrope, 
mative, bhie, white and cream ........5.00.0... Jal 
4. Shale, sandy, greenish, coarse, with dark limestone 
PermerOmeratie AL tO 22.2). oP eres ees LESS 30° 
5. Conglomerate and coarse sandstone, Shinarump 
conglomerate. 
300’ 


The Chinle is lthologically strongly in contrast with 
the underlying Shinarump conglomerate, which is sig- 
nificant, and which may indicate an unconformity though 
this does not necessarily follow. At the top of the Chinle 
along The Ledge there is no evidence of unconformity, 
for the Chinle seems to grade insensibly into the massive 
Wingate sandstone above. On the other hand, near Tem- 
ple Mountain there is a marked lithologic difference in 
the Chinke and La Plata which may perhaps indicate a 
time break. In the Navajo country east of Carrizo 
Mountain in extreme northeastern Arizona I found evi- 
dence of such a break betwen the Chinle and overlying 
Wingate sandstone, and Gregory obtained evidence of 
unconformity at this horizon at several other places in 
the-Navajo country.1* Thus it appears likely that the 
Chinle may be unconformably limited at the top and 
bottom. 

That the beds described above are to be correlated 
with the Chinle formation on the Navajo Reservation I 
think there is no reason to doubt. The peculiar lithologic 
characters of the Chinle in the Reservation, including 
the presence of limestone conglomerate, are duplicated in 
Green River Desert, and this together with its position 
between such prominent and unmistakable key-beds as 
the Shinarump below and the massive Wingate sandstone 
above, makes the correlation of the formations in the two 
localities imperative. The Chinle is identical with the 
beds referred by Gilbert to the (c) or upper division of 
his Shinarump group in the Henry Mountains region.** 
It is Triassic in age. 


% Gregory, H. E., op. cit., p. 48. 
8 Gilbert, G. K., op. cit., p. 6, stratigraphic section. 


564 Hmery—Green River Desert Section, Utah. 


La PLATA GROUP (JURASSIC). 


The La Plata group, which consists of three formations, 
includes all the beds between the Chinle and McHlmo and 
is probably hmited both above and below by unconform- 
ities. The lowest formation of the group is the Wingate 
sandstone, about 900 feet thick and composed of massive 
cross-bedded, quartz-sandstone beds. Above it lie 100-300 
feet of shale and gypsum, with a thin marine limestone 
containing fossil invertebrates of Jurassic age near the 
base, which are believed to represent the Todilto forma- 
tion of the Navajo Reservation. Massive cross-bedded red 
sandstone and thinner bedded red sandstone and sandy 
shale aggregating about 700 feet in thickness constitute 
the Navajo sandstone, which les above the Todilto (?) 
and is the highest formation of the La Plata group. The 
2roup as developed in Colorado, Arizona, and New Mex- 
ico has been referred to the Jurassic on account of strati- 
eraphic position, and that reference is now confirmed by 
the distinctive marine Jurassic invertebrates in the 
Todilto (?) formation. 


WINGATE SANDSTONE (JURASSIC). |, 


The Wingate sandstone, the lowest formation in the 
La Plata group, embraces all the massive cross-bedded 
sandstone between the Chinle and the overlying To- 
dilto (?) formation. It is widely exposed in Green 
River Desert, forming the canyon walls of Green River 
from the mouth of San Rafael River to Horseshoe Canyon 
and eapping The Ledge from there to the Dirty Devil. 
The wonderfully impressive crags of San Rafael Reef 
are formed from the Wingate sandstone. _ 

The Wingate is a remarkably uniform series of 
extremely massive, very cross-bedded, medium to fine- 
erained sandstones, averaging in this region about 900 
feet in thickness. The name Orange Cliffs, which 
appears on the Land Office base (1915) along what is 
locally and more expressly known as The Ledge, is a 
descriptive term derived from the color of the lower part. 
of the Wingate which forms these cliffs. The upper part 
of the formation near The Ledge is white. A similar 
color scheme is seen in the Wingate in San Rafael Reef 
in the vicinity of San Rafael River, but at other places 


Emery—Green River Desert Section, Utah. 565 


along the Reef the formation is white throughout its 
entire thickness. Such inconstancy of color seems to 
preclude its use as a diagnostic character, although it 
was regarded as distinctive by Powell, Dutton, and Gil- 
bert in their early reconnaissance work in Utah. The 
extreme massiveness and cross-bedding of these sand- 
stones, which features were of course recognized and 
emphasized by these writers, seem indeed to be diagnostic 
and to afford much safer ground for correlation pur- 
poses than does color. 

There is generally a weaker zone between the massive 
and resistant upper and lower portions of the Wingate 
in both The Ledge and San Rafael Reef, but this zone 
occurs at different stratigraphic positions in each section. 
In the section at The Ledge it is 250 feet thick and starts 
avo feet above the base of the formation, whereas in the 
Temple Wash section it is only about 200 feet thick and 
starts 150 feet above the base of the formation. The 
beds in this zone are sandstones similar to those above 
and below in all respects except that they are less mas- 
sive, and so less resistant to erosion. There is no shale 
or gypsum in this zone, but within a few feet of the top of 
it in the Temple Wash section are two beds of conglom- 
erate each less than 4 feet thick containing angular lime- 
stone and shale pebbles. These conglomerates le about 
500 feet below the top of the formation in this area. In 
the section at The Ledge similar conglomerate was noted 
‘about 100 feet below the top of the Wingate in the midst 
of a thick series of very massive sandstones, but no such 
conglomerate’ is present here in the less massive middle 
portion of the formation. Near the ‘‘Bowknot’’ loop of 
the Green fragments of fossil wood are present in similar 
conglomerate in the upper part of the Wingate. The con- 
glomerate is apparently only locally developed and is 
such as one would expect to form by the breaking up of 
limestone and shale deposits laid down in little fresh 
water lagoons. It marks no single definite horizon nor do 
the less massive sandstone beds in the middle portion of 
the Wingate represent a single period of widespread depo- 
sition of this type. Rather they indicate that at different 
times in different places conditions were right for the 
deposition of more thinly bedded sandstone than were 
laid down before or after. 


566 Emery—Green River Desert Section, Utah. 


The following sections illustrate the character of the 
Wingate sandstone: 


Section of Wingate sandstone in The Ledge near French Spring. 


1. Sandstone, white, weathering light buff to white, 
medium grained, very massive, cliff maker; cross- 
bedded, contains bed of limestone conglomerate 
about 100: below top. c sn saw. ee oe 289'+ 


2. Sandstone, lighter in color than underlying sand- 
stone, grading into white above, less massive than 
(1) and: (4), cross:bedded’< 4 sn.ic 13 ee 145’ 
3. Sandstone like (4) but less massive ............ 105’ 


4. Sandstone, orange-terra-cotta in color, weathering 
red-brown, very massive, a single bed; eross- 
bedded, very prominent ledge maker: j2sareenae 319 

5. Sandstone and shale, red-brown, Chinle formation, 


910’+ 
Section of Wingate sandstone, North Temple Wash. 
(Measured with the aid of Milton Anderson and Walt M. Small of Tulsa, 


Okla.) 
1. Shale and fossiliferous limestone, Todilto (7?) 
formation. 
2. Sandstone, white, massive, cross-bedded, forms dip 
slope of San Rafael” Reet 0. ss ee oe ee ay ae 


3. Sandstone, white, less massively bedded than mem- 

ber above, but having similar characters. Con- 

tains two thin beds of limestone conglomerate 

within’ 25 oF top: Pe ers Oa 213" 
4. Sandstone, hght buff, very massive, cross-bedded, 

cliff maker, supports San Rafael Reef; oil sand 


aiteWaSerdoe aiid sae 5 te Oka ieee eae 150’ 

5. Sandstone, red-brown, and variegated shale, Chinle 
formation. 

880’ 


The beds described above were divided by Gilbert into 
two formations, the ‘‘Vermilion Cliff’’ and the ‘‘Gray 
Chit apparently largely because of color differences, 
but that such a division was attended with difficulties is 
evident from Gilbert’s statements quoted below :1* | 

‘The Gray Cliff and Vermilion Cliff sandstones are often dif- 
ficult to distinguish, but the latter is usually the firmer, standing 


in bold relief in topography, with level top, and at its edge a 
precipitous face. The former is apt to weather into a wilderness 


‘Gilbert, Go 1K: op. eit, 9.1%. 


Emery—Green River Desert Section, Utah. 567 


of dome-like pinnacles so steep sided that they cannot often be 
scaled by the experienced mountaineer, and separated by narrow 
clefts which are equally impassible.’’ 


And again: 
‘Standing upon one of the summits of the Henry Mountains 
and looking eastward I found myself unable to distinguish the 


Gray Cliff Sandstone by color either from the lower part of the 
Flaming Gorge Group or from the Vermilion Cliff Sandstone.’’ 


The distinction of two formations in these massive 
sandstones is equally as difficult in the Green River 
Desert as in the Henry Mountain region. As already 
shown, color in these beds is not a sure ground for the 
drawing of formational boundaries, and in the absence of 
fossils I can see no basis for drawing such a boundary in 
the midst of a series lithologically similar from top to 
bottom. In my opinion the ‘‘Vermilion Chiff’? and 
‘“‘Gray Chiff’’ sandstones constitute a single stratigraphic 
unit, which is equivalent to the Wingate sandstone of the 
Navajo Reservation. This correlation is based on the 
position of the unit between the Chinle formation below 
and a series of limestone, shale, sandstone, and gyp- 
sum beds above which is believed equivalent to the 
Todilto as mapped by Gregory in the western part of the 
Navajo Reservation, and further upon its lithologic 
character, especially its massiveness and cross-bedding, 
which dupleate that found in the Wingate in Arizona. 
This interpretation differs from that of Gregory,!® who 
correlated the Wingate sandstone with only the lower 
part of the series, the ‘‘Vermilion Cliff’? portion, and 
who regarded the Todilto as the equivaient of the less 
massive zone present in the ‘‘ Vermilion Cliff’’—‘‘ White 
Cliff’? series of beds in the High Plateaus. It has been 
shown above that this less massive zone is not constant in 
stratigraphic position in Green River Desert, but does in 
fact oceur at various horizons in the series, and is not a 
formation or definite member of a formation. The pres- 
ent interpretation differs also from that of Doctor Cross, 
who im eastern Utah correlated the upper (‘‘ White 
Cliff’?’) portion of the series with the La Plata,® and 
regarded the ‘‘ Vermilion Cliff’? sandstone as older than 
La Plata. The present interpretation differs also from 

48 Gregory, H. E., op: cit., plate III. 


17 Cross, Whitman, Stratigraphic results of a reconnaissance in Western 
Colorado and Eastern Utah, Bull. Geol. Soc. America, 15, p. 642, 1907. 


Am. Jour. Sct.—FourtsH Series, Vout. XLVI, No. 274.—OctToBer, 1918. 
24 


568. Hmery—Green Rwer Desert Section, Utah. 


that of Lupton, who in the course of a study of the Cre- 
taceous beds in Castle Valley and again in Grand County 
near Greenriver, also briefly examined the underlying 
rocks and reached the conclusion that the massive 
Jurassic sandstones (‘‘Vermilion Cliff’? and ‘‘Gray 
Chff’’) represented the entire La Plata group.!* 


- Topiuto (?) ForMATION (JURASSIC). 


The rocks here cailed Todilto (?) formation constitute 
the middle portion of the La Plata group and comprise a 
heterogeneous and extremely variable series of shale, 
sandstone, limestone, and gypsum, but is a perfectly defi- 
nite unit between the Wingate sandstone below and the 
Navajo sandstone above. It is broadly exposed in Green 
River Desert just east of San Rafael Reef, and again 
back from the canyon of Green River and The Ledge. 

The Todilto (?) formation, characterized by its extreme 
variability, which is in fact diagnostic, in places appears 
as an unbedded jumbled mass of reddish shales associ- 
ated with dirty gypsum and irregular bunches of massive 
sandstone, as in the Dugout Creek area about 8 miles 
above the mouth of San Rafael River, but elsewhere 
comprises a series of regularly bedded shales, sand- 
stones, limestone, and gypsum, as for example, along 
Green River south of San Rafael River and in places 
along San Rafael Reef. The formation varies from 100 
to about 3800 feet in thickness. 

Near San Rafael Reef where the Todilto (?) 1s rather 
regularly bedded a persistent blue-gray, compact lime- 
stone 2 to 4 feet thick les from 12 to 15 feet above the 
base of the formation. This limestone is very fossil- 
iferous and in a collection made with the assistance of Dr. 
Harvey Bassler along the Greenriver-Hanksville road 2 
miles south of Straight Wash the following species have 
been identified by Dr. T. W. Stanton, who states they are 
marine invertebrates of Jurassic age: 


Ostrea strigilecula White Gervillia (?) sp. 
Camptonectes sp. Trigona quadrangularis 
Camptonectes stygius White Hall and Whitfield 
Plicatula sp. Cyprina (2) sp. 


7 TLupton, C. T., Oil and Gas near Green River, Grand County, Utah, 
U.S. Geol. Survey, Bull. 541, p. 125, 1914. 


Emery—Green River Desert Section, Utah. 569 | 


In driving from Castledale to Greenriver, Mr. H. S. 
Palmer and I noted fossils at this horizon at the north 
end of the Swell and Lupton reports this limestone to be 
fossiliferous in Castle Valley on the west side of the 
Swell, where in addition to the species listed above he 
found Modiola subrimicata Meek.'* 

Along Green River south of San Rafael River the 
limestone of the Todilto (?) directly overlies the massive 
Wingate sandstone. The limestone is here barren of fos- 
sils and is 4 feet thick, blue-gray, and dense in texture 
though it is possible to see flashes from crystal faces when 
a hand specimen is turned in the sun. With the lme- 
stone is interbedded chert, and in places there are irreg- 
ular patches of calcite. This limestone strongly reminds 
me of the Todilto limestone in the type locality at Todilto 
Park, north of Fort Defiance, Ariz. 

The sharp lthologic contrast of the Todilto (?) and 
Wingate and especially the much disturbed character of 
the lower beds of Todilto (?) in some places suggests 
that these formations are separated by an unconformity. 
The pronounced irregular surface of the top of the 
Todilto (?) into which the overlying Navajo fits, sug- 
gests that the Todilto (?) is also limited above by an 
unconformity. 

The following detailed section furnishes an idea of the 
character of the Todilto (?) formation in the Green River 
Desert: 


Section of Todito (2?) formation im sec. 28 T. 24 S., 
R. 16 E., Salt Lake Meridian, Utah. 


1. Sandstone, red, massive, cross-bedded Navajo sand- 
stone. EHrosional unconformity ? 


2. Sandstone, like (4), contact with massive red sand- 
SCIIE IGA ASG TG Te oem pee ies nea ge eet ee eS are 6 
3. Sandstone, light-colored, weathering leht green; 
coarse-grained, irregularly bedded ............ Te 


4. Sandstone, dark red, coarse-grained, rather irreg- 
ularly bedded, with ripple-marked layers 47-15” 
AUIMICIE pens teeta eg We See ae rahe et ah a ee ae 68’ 
Sandstone, pinkish gray, massive, cross-bedded 


Wingate sandstone. 


OV 


95’ 


8 Lupton, C. T., Geology and coal resources of Castle Valley, in Carbon, 
Emery, and Sevier counties, Utah, U. 8. Geol. Survey, Bull. 628, p. 24, 1916. 


570 Emery—Green River Desert Section, Utah. 


Of the Jurassic age of the rocks just described there 
can be no doubt, for it is amply shown by the fossil con- 
tent. They are lithologically similar to beds referred 
by Gregory to the Todilto in Piute Canyon and near Nay- 
ajo Mountain, and like those beds lie between massive 
Wingate sandstone, below, which is an excellent key 
formation, and the Navajo sandstone above. Gregory, 
however, states that the expression of the beds in the 
northwest part of the Navajo Reservation is so unlike the 
Todilto of the type locality that the correlation can only 
- be considered a working field hypothesis.1° So while it 
is recognized that the beds between the Wingate and Nav- 
ajo in Green River Desert are the equivalent of similar 
beds near Navajo Mountain they are referred to the 
Todilto with a question mark because later work may 
show that the Navajo Mountain Todilto is not indeed the 
equivalent of the type Todilto. ; 

The Todilto (?) constitutes the lower part of what Gil- 
bert termed the ‘‘Flaming Gorge group’’ in the vicinity 
of Henry Mountains and has been included by Lupton in 
the McHlmo in Grand County and in Castle Valley. 
Lupton, however, was aware that the inclusion of these 
beds in the McElmo might not stand the test of more 
detailed work than the time at his command and the exi- 
gences of his examination permitted, for in this connec- 
tion, quoting a list of fossils found in the limestone men- 
tioned above, he said: 


‘‘As the McElmo formation in its type area is not known to 
include any marine strata, it is possible that the bed contaiing 
this fauna is older than the basal beds of the typical McElmo.’’”° 


Navajo SANDSTONE (JURASSIC). 


The Navajo sandstone includes the beds between the 
Todilto (2) formation and the variegated shale and 
coarse sandstone and conglomerate of the Salt Wash 
member of the McHlmo. It is broadly exposed in Green 
River Desert outcropping along San Rafael River and 
also in the region of the Flat Tops. : 

In the field two members of the Navajo sandstone were 
mapped on lithologic grounds. The lower of these is 
about 300 feet thick and consists of medium-grained sand- 

1“ Grecory, Hi. E., op. cits.) p:)50. 

*° Lupton, C. T., Geology and coal resources of Castle Valley, in Carbon, 
Emery, and Sevier counties, Utah, U. S. Geol. Survey, Bull. 628, p. 24, 1916. 


= 


Limery—Green River Desert Section, Utah. 571 


stone, Massive in character, and much cross-bedded and 
held together by caleareous cement. True bedding is so 
irregular as to make it next to impossible to obtain a val- 
uable dip reading with the clinometer and the irregular- 
ity is especially marked near the contact with the 
Todilto (?) into the irregularities of which the lower 
Navajo beds fit. The irregularity along this contact 
suggests an unconformity at this horizon. In general 
the color of the lower massive Navajo is brick-red 
but in places near the ‘‘Reef’’ the rocks vary in color 
from café-au-lait to straw. This part of the formation 
weathers into prominent cliffs with rounded, impassable 
faces, or into deep pockets which catch and retain rain 
water. A rather local and striking feature of weathering 
is that near Gillis’s ranch on San Rafael River where 
the formation is veined with calcite—probably associated 
with minor faulting, and weathers into low walls which 
‘‘fence’’ in circular areas. 

The thin-bedded upper part of the Navajo contrasts 
strongly with the massive lower part just described. 
The beds are sandstone and sandy shale and are for the 

aost part brick-red in color, but near the middle of the 
series 1S a conspicuous zone of light-colored beds which 
though of similar lithology to the associated beds, differ 
in that they are light greenish in color. With them are 
associated irregular bunches of quartz which weather 
into small rounded red balls or lozenges resembling in 
appearance red rubber bath sponges. These ‘‘sponges’ 
may be seen in profusion along the Hanksville road two 
miles or so south of San Rafael bridge. The very top of 
the upper Navajo sandstone is characterized by a 90-foot 
chff of sandy shale interbedded with dirty gypsum. 
There is about 15 feet of almost solid gypsum just below 
the McHImo, which is thought to uncomformably overlie 
the Navajo. 

The character of the Navajo sandstone is shown by the 
following section: 

Section of the Navajo sandstone near Gillis’s ranch, 
San Rafael River, Utah. 
1. Shale and thin sandstone with much interbedded 
gypsum, 15’ of gypsum at top makes a vertical 

Ca Certain CEN ny Rate BR ae TOR kg ob 90’ 
Shale, sandy, brownish, with interbedded gypsum, 

forms steep slope to cliffs above .............. 63’ 


bo 


572 Hmery—Green River Desert Section, Utah. 


3. Sandstone and sandy shale, light brown below, 
greenish above, thin-bedded, some beds 1/16” 
thick, with veins and interbedded layers of gyp- 
sum 6. to 18” thick in middle portion 7....2... 144’ 
4. Sandstone, fine-grained, reddish brown on weathered . 
surface, somewhat lighter on fresh fracture, lower 


part massive, upper part more thinly bedded ...  —- 1277’ 

5. Sandstone, massive, cross-bedded, red-brown to yel- 
lows: Histimiadted “AQ Sa, a 300’ 
724’ 


The pads described above were included by Gilbert! 
in the ‘‘Flaming Gorge group’’ and have been referred 
by Lupton”? to the MeElmo formation. Their lithologic 
character and stratigraphic position are suggestive of 
the Navajo sandstone of northeastern Arizona, and 
accordingly all the beds in Green River Desert between 
the Todilto (?) and the Salt Wash member of the 
McElmo have been referred to that formation. The 
limits of the Navajo as thus drawn are very definite in 
Green River Desert, but it is realized that the upper 
limit here may differ somewhat from that on the Reser- 
vation where Gregory states that the boundary hetween 
the Navajo and McElmo ean not be too finely drawn.”* 
That the contact in the two areas is not identical seems 
likely for Gregory has included the beds of Theater 
Rock in the McEImo while what appear to be similar beds 
in Green River Desert are here referred to the Navajo. 
Realizing that in northeastern Arizona there is appar- 
ently no counterpart of the Salt Wash member of the 
MecEImo, which I believe indicates an unconformity, and 
realizing that the contact of the Navajo and McKImo is 
therefore uncertain in some degree, I have drawn the 
boundary as sharply as possible in Green River Desert. 
As so drawn, the Navajo contains all the red cross-bedded 
-gandstone and red sandy shale above the Todilto (?); 
the McElmo includes light-colored coarse sandstone and 
variegated shales entirely different in character from the 
beds in the Navajo. 

McEumMo ForMATION. (CRETACEOUS?) 

The MeElmo formation overlies the Navajo sandstone 
and includes all the beds between it and the Dakota sand- 

2E Gilberts Grate OPancit..0 D4 O. 


ep bons On vl. Oct 
2 Gregory, H. E., op. cit. 


Emery—Green River Desert Section, Utah. 578 


stone, or Mancos shale where the Dakota is absent. The 
formation embraces a series of coarse sandstones, con- 
glomerates and variegated marl-like shale, and may be 
divided into. three parts on the basis of lthology. Of 
these the lowest consists of coarse sandstone and con- 
olomerate with minor amounts of light shale and has been 
called the Salt Wash member, by Lupton.*t— The middle 
portion embraces a series of variegated shales with local 
thin sandstones, and the upper portion consists of hard 
sandstone which weathers dark and has associated with it 
small amounts of variegated shale. 

At the base of the Salt Wash member of the McKlmo 
formation is 15 to 20 feet of light variegated shale which 
contrasts strongly in lithology and color with the under- 
lying Navajo sandstone. The Salt Wash member is 200 
feet thick, and with the exception of the basal shale, con- 
sists of coarse sandstone composed of loosely cemented, 
rather well rounded quartz grains mostly translucent 
with a small per cent of weathered feldspar. It also 
includes considerable poorly cemented conglomerate. 
These rocks are light-colored on fresh fracture and in 
many places weather nearly white, though elsewhere they 
weather a light brownish color. Fragments of light-col- 
ored petrified wood are present in this series and with 
them are associated in a number of places yellow streaks 
in irregular blotches of carnotite, and other uranium and 
vanadium ores. Many uranium claims have been located 
on the outcrop of this part of the formation in the vicinity 
of San Rafael River and numerous prospect holes have 
been opened. The Salt Wash member also includes 
numerous fragments of dinosaur bones which differ from 
the dinosaur bones in the overlving beds in that they 
are smaller. 

The présence of shale very different in character from 
the underlying Navajo beds, and the further presence of 
a considerable thickness of conglomerate and coarse sand- 
stone indicates that deposition in Salt Wash time took 
place under conditions entirely different than those pre- - 
vailing before that time. The evidence indicates that. 
Salt Wash deposition was separated from the Navajo by 
a time break, and that the contact-of the Navajo and 
McElmo is unconformable. 


*4 Lupton, C. T., Oil and gas near Green River, Grand County, Utah, U. S. 
Geol. Survey, Bull. 541-D, p. 15, 1914. 


574. Emery—Green River Desert Section, Utah. 


A detailed section showing the character of the Salt 
Wash member of the McElmo is given below. 


Section of the Salt Wash sandstone member of the 
MckKlmo formation. 


On north side of San Rafael River two miles below San Rafael bridge. 


1. Sandstone, coarse-grained, loosely cemented; con- 

tains: fraements: of fossil: woods: ..i2))... cee ee 20’ 
2. Shale, green to gray in color and streaked with 

brown; irregularly bedded; streaked with yellow 

at top and bottom indicating presence of carno- 

HEU ie MR nears he te oc Vea Caen gs A PP ee Sy 5 
3. Sandstone, hght-colored on fresh fracture, weather- 

ing dark brown medium to coarse-grained, 


loosely cemented, soft, cross-bedded, massive .. 55! 
4. Shale, variegated light and maroon ...:........4-. ee. 
5. Sandstone, light-colored, fine-grained, ledge-making 

but not as hard as sandstones lower in section .. 6’ 


6. Shale, mostly heht-colored but with some maroon, 
and with one sandstone bed one-half way up 
which is here 1144 feet thick, but elsewhere 5’ 


td@le sso tc dae ek ts etnies Bes ok Ra Se ee 30’ 
7. Sandstone, like 9, ledge-making in places ..... pe 8’ 
8. Shale, lke that lower in section, mostly maroon ... iby 
9. Sandstone, like 11 and 13, somewhat irregularly 

bedded and streaked with maroon shale ........ gh 
10. Shale, mostly maroon but with some light colors, 

and “with local: sandstone: . isis 1o ee eee alt! 
Vii Sandstone, likets 453 oa ore at oe er 3° 
12 Shales tke 14 bith wath more maroon) )= see 9’ 


3. Sandstone, nearly white on fresh fracture, weathers 

heht brown, hard, compact, very fine-grained, a 

siole bed with. thimdlaminae. «42 24 eee oy 
14. Shale, variegated light green with some maroon and 
contains some thin sandstone, Base of Salt Waash 
Sandstone member ic) a’. oe ee ay 


Above the Salt Wash member of the McElmo lies a 
series of variegated clay shales 170 to 200 feet thick, 
which weather into steep cliffs and are very conspicuous 
because of their gray, purple, and maroon colors. The 
shales contain numerous well-polished pebbles 14 to 2 
inches in diameter, resembling gastroliths, which are 


Emery—Green River Desert Section, Utah. 575 


found in profusion strewing weathered surfaces, and also 
contain toward the top bones of large dinosaurs. The 
variegated shales are capped by a bed of coarse sandstone 
or conglomerate which forms a prominent bench, and 
above which is a series of coarse sandstones and con- 
glomerates with small amounts of gray or pale-tinted 
variegated shale. This part of the section is extremely 
variable in lithology and color but is in general charac- 
terized by a predominance of sandstone which, though 
hight on fresh surface, is Somber gray or black in color 
on the weathered face due to’ desert varnish. The 
accompanying stratigraphic section gives details of the 
beds in the McElmo formation above the Salt Wash 
member. 

Section of upper part of the McElmo formation three-fourths 
mile west of Jesse’s Twist in the Greenrwer- 
Hanksville road. 

(Measured by Milton Anderson.) 

1. Conglomerate, light-colored, massive, cross-bedded sy 
2. Shale, light-colored, sandy, containing beds of gray- 

1 Sul oo SETI CIR ECC Tea Oye rca ae ae oe 
3. Conglomerate, grayish in general color, but contain- 
ing well worn, red, blue, black quartz pebbles, 
loosely cemented, makes a ledge ............... 25 
4. Shale, gravish purple, containing four thin beds of 
sandstone and capped by layer of white shale two 


ie epmmnNy rey Coates held 1k Sie ORE Re 8 38’ 
5. Sandstone, brownish gray in color, in beds 18” thick 

alternating with purple and gray shales ........ 15’ 
6. Sandstone, brownish gray, coarse- oa irregu- 

lane beaded. ledge. maker: <2 2. rs ke 20’ 
7. Shale, varievated purple, gray, red, caine well- 


polished pebbles resembling gastroliths, with local 
MeMnIsamMaShomecbeds: ski woke oS ee ee 170’ 


CLOLP NES eae 2a ie Sach cree Nes Re ee Ra ae SEP se a 308" 


The beds just described and included by Gilbert?* in 
the ‘‘Flaming Gorge group,’’ were referred to the 
McElmo by Lupton,?° who also placed in this formation 
the underlying Navajo and Todilto. In the present 
paper these two, formations have been referred to the 
La Plata group of rocks (Jurassic) for reasons already 
presented. The lower limit of the McKIlmo (Cretaceous?) 


= Galbert,, G. i... 0p. it. 
“upton, C..T., op. cit. 


576 Hmery—Green Rwer Desert Section, Utah. 


is placed at the base of the Salt Wash member of this 
formation because there is at this horizon a distinct 
lithologie and color break, which with the presence of a 
thick series of coarse sandstone is indicative of a time 
break and unconformity. The upper limit of the 
McElmo is the Dakota sandstone, or Mancos shale where 
the Dakota is absent. As so defined the McEKImo appears 
to be in accord with the description of the McElmo at the 
type locality along the creek of that name in southwestern 
Colorado where it consists principally of marl-like varie- 
gated shales. 


DaKoTA SANDSTONE (CRETACEOUS). 


The Dakota sandstone is exposed near the Greenriver- 
Hanksville road in the vicinity of Greenriver where it 
reaches a maximum thickness of about 40 feet but is 
absent elsewhere in the northern part of Green River 
Desert. It consists of loosely cemented and friable, 
coarse sandstone layers and lenticular beds of coarse 
conglomerate containing rather well rounded translu- 
cent, gray, black, and red quartz pebbles. On fresh frac- 
ture the color is buff but the rock commonly weathers to 
arusty dark brown. No coal was observed in the Dakota 
in the Greenriver region nor were. any fossils collected 
in the rather cursory examination of the formation, but 
Richardson?’ who studied the Dakota in this vicinity as 
well as over a large area to the east and west found 
characteristic Dakota plants (Cretaceous) in it near 
Elgin, and therefore has correlated it with the Dakota of 
the Rocky Mountain region. It is unconformable on 
the underlying variegated shales and sandstone of the 
McKImo. 


Mancos SHALE (CRETACEOUS). 


The Maneos shale overlies the Dakota sandstone and 
is broadly exposed in the vicinity of Greenriver and 
along the base of the Book Cliffs for many miles east and 
west of that town. It comprises a series of rather uni- 
form drab to dark gray clay shales, which are calcareous 
throughout, in places to such an extent as to be almost > 
limestones. About 200 feet above the base of the forma- 
tion and forming a prominent escarpment is 15 to 20 feet 


7 Richardson, G. B., Reconnaissance of the Book Cliffs Coal field, U. S. 
Geol. Survey, Bull. 371, p. 14, 1909. 


Emery—Green River Desert Section, Utah. 577 


of shale more resistant than the rest of the formation 
and which erodes into small lozenges, steel gray on the 
weathered face. This together with the tendency of the 
shale to rmg when trod upon leads one to suspect that it 
may represent the Mowry shale of Wyoming which lies 
in a somewhat stratigraphically similar position. With 
this resistant shale are associated, near Tidwell, minor 
sandstones containing sparsely distributed, small black 
quartz pebbles with which were found fragments of 
Inoceramus sp. and sharks’ teeth belonging to Lamna and 
possibly other genera. The black quartz pebbles sug- 
gest that these beds may represent in this region the 
sandstones of the Frontier formation of Wyoming. 

The following species identified by Doctor Stanton as 
Benton in age were collected from calcareous sandstone 
nodules in the shale about 50 feet above the base of the 
formation 3 miles northwest of the Greenriver-Hanks- 
ville road: 


Gryphaea newberryt Stanton Exogyra suborbiculata lLa- 
Plicatula? sp. marck? 
Cardium pauperculum Meek Veniella martona M. and H. 


Gryphaea newberryt Stanton oceurs profusely at the very 
base of the formation and fragments of Inoceramus sp. 
are widely distributed through the lower part of the 
series. 

Richardson, Lupton and others who have studied this 
shale near Greenriver have correlated it with the Mancos, 
and fossil evidence amply confirms the correlation. The 
more resistant band of shale described as lying about 
200 feet above the base of the formation is to be cor- 
related I think with the Ferron sandstone member of the 
Mancos,”* for although this part of the shale cannot be 
actually traced into the Ferron east of Greenriver yet the 
distance between the two outcrops is so small and their 
stratigraphic position is such that there can be no doubt 
of the correlation. 


*8 Lupten, C. T., op. cit. 


578 Jonson—The Law of Dissipation of Motion. 


Arr. XXIV.—The Law of Dissipation of Motion; by 
Hirnnst JONSON. 


In order to explain the physical aspect of the universe 
it is assumed that matter consists of separate particles 
tied together by forces in such a manner that when the 
particles move motion is transmitted from one particle 
to another. Transmission of motion is mechanically con- 
ceivable only if we assume that.a force acts on the two 
particles between which transmission of motion takes 
place, 2. e., when the two particles are the points of 
application of a force. 

When two stars revolve about their common center of 
gravity there occurs a continuous transmission of motion 
from each one to the other. Such transmission of motion 
involves permanent action of force. When a water mole- 
cule collides with an iron molecule in the wall of a steam 
cylinder the resulting transmission of motion is momen- 
tary because the force acts only for an instant. The 
revolution of masses of matter about each other is a 
comparatively stable condition. Most natural changes 
evidently are due to transmission of motion through col- 
lision. In the mechanics of collision then must be found 
the final explanation of all those natural phenomena 
which result from the transmission of molecular energy. 

The following derivation of the Law of Dissipation of 
Motion is a contribution to this branch of mechanics. 
The chief immediate interest in this law arises from the 
fact that it explains the Law of Dissipation of Hnergy 
by rendering its mode of operation mechanically present- 
able. 

When a collision occurs between two particles and the 
motions of the colliding particles are not parallel, each 
motion may be resolved into two perpendicular compon- 
ents in such a way that each component of one motion is 
parallel with one of the components of the other motion, 
and so that the two components which have the same 
direction also have the same size. The momentum AB 
in figure 1 is resolved into the momenta AD and DB, and 
the momentum CB into the momenta CD and DB. The 
two coinciding components of the original motions repre- 
sent the common motion of the two particles and have 
therefore nothing to do with the collision. The collision 
of the two particles results, of course, entirely from their 
relative motion. This relative motion is represented by 


Jonson—The Law of Dissipation-of Motion. 4579 


the two components AD and CD which are of opposite 
direction. 

The probability that the paths of initial motion of two 
colliding particles will exactly coincide is zero, because 
there is an infinity of possible degrees of eccentricity of 
collision. The actual relative motion of two colliding 
particles, therefore, must be regarded as eccentric. 

When two moving particles collide and thus become the 
points of application of a force each particle receives 
from the other an additional momentum of the same 
numerical magnitude but of opposite direction. If the 
paths of initial motion of the two particles do not coin- 


Pres 


be) 


D 
S 


cide these added motions are not parallel with the initial 
motions, but the added motion is a deflecting motion as 
indicated in figure 2. 

Take two particles with the respective initial momenta 
AB and BOC, each receiving an additional momentum, the 
momentum BD being added to AB and the momentum 
DB to BC. If one of the initial momenta, say AB, is 
ereater than the other initial momentum, BC, the dif- 
ference AC between the two initial momenta is greater 
than the difference between the two resultant momenta 
AD and DC.. To demonstrate this proposition it is neces- 
sary only to consider that since the sum of the lengths of 
two sides of a triangle is greater than the length of the 
third side AC plus DC is greater than AD. If DC be 
deducted from both quantities it is seen that AC is 
greater than AD minus DC. In other words, the differ- 
ence between the initial momenta is greater than the 
difference between the resultant momenta. 


580 Jonson—The Law of Dissipation of Motion. 


The possible relations of magnitude which may exist 
between AB and BC are infinite. Hence, the probability 
that these two momenta are equal is one divided by 
infinity, 2. e., zero. In every actual transmission of 
momentum the initial momenta must be regarded as dif- 


Bie. 2. 


D 


B 


fering in magnitude, and, as has been previously shown, 
as not coincident in their paths. Hence, it must be con- 
cluded that in every actual transmission of momentum 
the difference in momentum is decreased, which means 
that momentum or motion is dissipated. The Law of 
Dissipation of Motion accordingly may be formulated as 
follows—every transmission of motion through collision 
is attended with a dissipation of motion. 

Knergy has two phases, energy of motion and energy 
of position. - In a collision motion only is transmitted. 
However it is highly probable that all transmission of 
molecular energy occurs through a transmission of 
motion through collision. If this assumption be granted 
the Law of Dissipation of Energy has been explained 
mechanically. The foregoing study of the problem of 
collision makes it clear how energy dissipates itself, and 
why energy is never concentrated as a result of physical 
process. ; 

1101 Aeolian Hall, New York City. 


Rogers—American Occurrence of Periclase. 581 


Art. XXV.—<An American Occurrence of Periclase and 
its Bearing on the Origin and History of Calcite-Bruc- 
ite Rocks; by Austin F. Rocsrs. 


1. The Occurrence of Periclase at Riverside, California. 


The rare magnesium-oxide mineral, periclase, not pre- 
viously known from this country, has recently been recog- 
nized in a specimen of crystalline limestone kindly sent 
to me by Mr. Lazard Cahn of Colorado Springs. This 
specimen was found by Mr. Cahn at the City quarry in 
Riverside, California. The limestone is a medium- 


WH] 


Lil 


a 
NaN 

/] “iia: i 
pe) 


I] 
i 


I" 
Wp 
NN 
Wh 


i 
NON 
U 
Hf 


Y 


if 
i 


i 
in 


. 


1) 
{] 


~ 


Fic. 1. Thin section (x 18) showing core of periclase within brucite. 
Riverside, California. 
grained rock consisting largely of calcite and dark gray 
to brown spots of brucite from 1 to 3 mm. in diameter. 
The periclase occurs as cores of 1 mm. maximum size 
within some of the brucite spots as shown in fig. 1. The 
periclase is a colorless mineral with perfect cubic cleav- 
age. Crushed fragments are square or rectangular in 
shape, dark between crossed nicols and have an index of 
refraction greater than 1-740. It is soluble in aqua regia 
and thé solution gives a good test for magnesium and a 
slight test for iron. 

Under the microscope the brucite proves to be an 
aggregate made up of concentric layers with a fibrous 
structure, the fibers having an elongation parallel to the 
faster ray. An attempt is made to illustrate this struc- 
ture in fig. 1. The brucite shows anomalous interference 


582 Rogers—American Occurrence of Periclase. 


colors, a peculiar reddish-brown hue taking the place of 
the orange and red of the first order.t. The indices of 
refraction determined by imbedding fragments in index 
liquids were found to be ny = 1:583 + -003, and ma = 
1-567 + -003. The brucite is clearly an alteration product 
of the periclase. 

Besides calcite, periclase, and brucite, the other min- 
erals present in the limestone are pyrrhotite, olive-green 
spinel (x > 1-740), magnetite, antigorite, and a colorless 
mineral occurring in rounded grains and subhedral ecrys- 
tals which is identified as a member of the chondrodite 
croup by the indices of refraction ny = 1-637 = -003; 
na —= 1607 + -003. These maximum and minimum 
values of the indices of refraction were determined by 
the immersion method. A few of the chondrodite crys- 
tals show polysynthetic twin lamelle with a maximum 
extinction angle of about 30° and this distinguishes it 
from humite and clinohumite. 

This occurrence is interesting not only on account of 
the presence of periclase but also because of its bearing 
on the origin and history of calcite-brucite rocks. 


2. The Origin of Calcite-Brucite Rocks. 


Calcite-brucite rocks were first described from Pre- 
dazzo in Austrian Tyrol under the supposition that they 
represented a distinct mineral with the composition 
CaCO,.Mg(OH), which was called predazzite. Damour 
showed that the predazzite was a mixture of calcite and 
brucite. His conclusion was accepted until Lenecek? in 
1891 decided that the mineral associated with the ealcite 
is hydromagnesite instead of brucite and since that time 
there has been some doubt as to the nature of predazzite.® 

Besides the Riverside occurrence the writer has studied 
two other American occurrences of dedolomitized lime- 
stones which contain but small amount of silicates and 
finds brucite to be present in abundance. In one of these 
occurrences hydromagnesite occurs and the relation of 

* Weinschenk (Petrographic Methods, translation by Clark, p. 244) 
speaks of ‘‘tombac brown, anomalous interference colors, which indicate 
a very low double refraction that approximates that of chlorite.’’ The 
last part of this statement is incorrect, for brucite has fair maximum 
double refraction, about 0-021. The interference color in a section about 
0-032 mm. thick (determined by taking the highest interference color of 
the chondrodite) reaches as high ‘as blue of the second order. 

2Min. petr. Mitt., 12, 429-442, 447-456, 1891. 


* Kemp, for example, in the olossary of hic Handbook of Rocks Says, 
‘“It is partly calcite and partly brucite or hydromagnesite.’’ 


Rogers—American Occurrence of Periclase. 988 


the brucite to the hydromagnesite could be determined. 
Fig. 2 shows the general character of the calcite-brucite 
eel in thin ane 


3. Calcite-Brucite Rock from Crestmore, California. 


A white crystalline limestone occurring in contact with 
eranodiorite at the Chino Hill quarry of the Riverside 
Portland Cement Company at Crestmore, about eight 
miles from Riverside, California, contains a pale pinkish 
gray mineral which has been identified as brucite by 
Kakle.t The brucite occurs in crystalline aggregates like 
those in the Riverside rock just described. The indices 
hiiferraction were found to be: .»y.— 1-583 + :003; 
Na = 1-563 + -003. The brucite is evidently an alteration 
product of periclase though no trace of the latter mineral 
was found. The form of the original periclase has been 
preserved as rough equant crystals, which are oscillatory 
combinations of the dodecahedron and octahedron, in 
habit much like a diamond crystal illustrated by Fers- 
mann and Goldschmidt.® 

The limestone also contains small amounts of minute 
colorless, rounded subhedral crystals of chondrodite.® 
They were isolated by dissolving the rock in dilute hydro- 
ehloric acid and were identified by the following indices 
Gutermacion: ny, — 1:643 +--003;. mm =—.1-613 =. -003. 

The residue from the hydrochloric acid solution also 
contains a colorless, optically isotropic mineral in the 
form of rounded equant subhedral crystals which is 
probably spinel (vn — 1-715 + -005)* and a few subhedral 
prismatic crystals of apatite as a nitric acid solution of 
the rock gives a faint test for the phosphate radical. 
This mineral is not wilkeite,’ which is found in the adjoin- 
ing quarry for no sulphate test was obtained. 

On the exterior of some of the limestone specimens the 
pinkish gray brucite gives place to an opaque white 
mineral which is identified as hydromagnesite. It is 

*Hakle, University of California Publications, Bull. Dept. Geol., vol. 
10, pp. 327-360, 1917. The analysis gives MgO 67-48, FeO, 0-55, H.O 
31-73 — 99.76. 

° Der Diamant, Atlas, Taf. 14, fig. 98, Heidelberg, 1911. 

°Hakle (loc. cit. p. 333) ineludes chondrodite in his list of minerals 
from this locality, but says that there is no well authenticated proof of its 
existence in the quarries. 

"Rankin and Merwin (Jour Am. Chem. Soce., 38, 512, 1916) find the 


index of refraction of pure spinel (MgAIl.,0,) to be 1-718 + -002. 
*Eakle and Rogers, this 7ournal, 37, 262-267, 1914. 
Am. Jour. Sct.—FourtH Srrizs, Vou. XLVI, No. 274.—Ocroser, 1918. 


20 


584 Rogers—American Occurrence of Periclase. 


undoubtedly an alteration product of brucite, for in thin 
sections it has the same structure as the brucite but can 
be distinguished from the latter mineral by the fact that 
the upper first-order interference colors are normal. Its 
double refraction is about the same as that of brucite but 
the indices of refraction are less than 1-55. 

One specimen showed the result of a still further altera- 
tion, that of the hydromagnesite to a weak doubly refract- 
ing, though probably amorphous,’? hydrous magnesium 
silicate which seems to be deweylite. It is a colorless to 
pale green, compact mineral with an index of refraction 
of 1-530 e*-008. 

The portions of limestone containing the deweylite 
have evidently had a very complicated history. The fol- 
lowing are the probable stages through which it has 
passed: 

Sedimentary limestone. 

Dolomitic limestone. 

Dedolomitized limestone with periclase. 
Calcite-brucite rock. 
Calcite-hydromagnesite rock. 
Caleite-deweylite rock. 


This furnishes another illustration of the fact that the 
minerals of a given rock or mineral deposit are formed 
in stages one after another. Notwithstanding statements 
to the contrary the contact-metamorphic deposits form 
no exception to this general rule. The dedolomitization 
and the consequent formation of periclase, chondrodite, 
spinel, and pyrrhotite are the result of high-temperature 
ascending solutions, presumably emanating from the 
magma. ‘The minerals just mentioned were probably 
formed in stages also, but no evidence on this point was 
obtained. 

The Crestmore occurrence is especially interesting 
because of the later after-effects of contact metamorph- 
ism. 

The formation of brucite at the expense of periclase is 
clearly later than the contact metamorphism and is prob- 
ably due to a hypogene’® process, for in the Riverside: 

*See paper by the writer on amorphous minerals, Jour. Geol., 25, pp. 
515-541, 1917. 

© This useful term was intr oduced by Ransome (U. S. Geol. Surv., Bull. 
540, pp. 152-3, 1914) for minerals or ores formed by ascending solutions. 
It and the corresponding term, supergene, used for minerals and ores 


formed by descending solutions, avoid the ambiguity in the use of the 
terms primary and secondary. 


D> U1 He O9 DO 


Rogers—American Occurrence of Periclase. 985 


occurrence secondary magnetite occurs in the brucite 
ageregates and seems to have been formed in part at 
least from the iron of the original periclase. Magnetite 
is a typical hypogene mineral usually formed at compara- 
tively high temperatures and in no known occurrence 
does it appear to have been formed from descending 
meteoric waters. 

The formation of a mineral containing such a large 


Rigo: 


Fie. 2. Thin section ( x 30) of calcite-brucite rock (b = brucite, ¢ = calcite). 
Mountain Lake mine, Utah. 


percentage of water as brucite (H,O — 30-8 per cent) by 
ascending solutions is unusual but not improbable. 

Whether the hydromagnesite is a hypogene or super- 
gene mineral is difficult to say. The problem of deter- 
mining the end of the hypogene stages and the beginning 
of the supergene is an important one, but very difficult 
in the present state of our knowledge. All possible data 
bearing on this problem should be recorded in every 
description of any kind of a mineral occurrence whether 
ore-minerals are present or not. It seems reasonable to 
regard the deweylite as a supergene mineral. 


4. Calcite-Brucite Rock from the Mountain Lake Mine, near 
Salt Lake City, Utah. 


Another brucite-bearing crystalline limestone from a 
contact zone at the Mountain Lake mine, near the head 


586 Rogers—American Occurrence of Periclase. 


of Big Cottonwood Canyon, twenty-five miles southeast 
of Salt Lake City, Utah, has been studied by the writer. 
Calcite and brucite are practically the only minerals 
present. The brucite occurs in subhedral, more or less 
rounded, equant aggregates which have exactly the same 
structure as the Riverside and Crestmore specimens and 
are doubtless pseudomorphous after original periclase. 
Fig. 2 shows the general character of the rock in thin 
sections which is almost identical with a predazzite from 
Fassathal, Tyrol. 


5. Other Occurrences of Calcite-Brucite Rocks in the Umted 
States. 


Emmons and Calkins'! report a crystalline limestone 
from the Phillipsburg quadrangle, Montana, which con- 
tains brucite and which they say is pseudomorphous after 
some unidentified mineral. The original mineral was 
_ probably periclase as they speak of brucite occurring in 
‘‘acoregates of microscopic fibrous or scaly individuals”’ 
and dedolomitized rocks are prominent in the region. 


Summary and Conclusions. 


1. The first recorded American occurrence of periclase 
is at Riverside, California, in a crystalline limestone. 

2. Calcite-brucite rocks (the so-called predazzite) are 
formed from periclase-bearing limestones by the altera- 
tion of periclase to brucite. 

3. The hydration of periclase to form brucite is prob- 
ably brought about by hydrothermal ascending solutions 
in spite of the fact that brucite contains about thirty-one 
per cent of water. 

4. Ata later stage the brucite may be converted into 
hydromagnesite, a mineral similar to brucite in general 
characters and one that may easily be mistaken for 
brucite. 

5. In crystalline limestones as in other rocks and 
mineral deposits in general the minerals are formed in 
stages one after another. 


Stanford University, California. — 


oy Ut. .Geol. SULV.,, ETOt: Paper oO, ps toi, loko 


Van Name and Huff—Hypophosphates. 587 


Art. XX VI.—On the Preparation of Hypophosphates; by . 
R. G. VanName and Wiipert J. Hurr. 


(Contributions from the Kent Chemical Laboratory of Yale Univ.—ccciii.) 


Hypophosphorie acid and its salts are usually prepared 
by the oxidation of yellow phosphorus. This may be 
accomplished either by the slow action of the air upon 
sticks of phosphorus partly submerged in water (the 
original method, due to Salzer’), or by the gradual addi- 
tion of the phosphorus to a warm acid solution of copper 
nitrate (Corne?), or of silver nitrate (Philipp?). It may 
also be prepared by the electrolytic oxidation of copper 
phosphide used as anode in dilute sulphuric acid (Rosen- 
heim*). In all these cases phosphoric and phosphorous 
acids are formed at the same time, but on converting the 
three acids into their sodium salts the difficultly soluble, 
acid sodium hypophosphate, Na,H.P.O,.6H.O, separates 
first from the solution, and can be purified by recrystal- 
lization. This salt is consequently the usual starting 
point for the preparation of hypophosphorie acid and its 
compounds. 

The first of the above reactions is the one which has 
received the most attention, and is the basis of several of 
the methods described in the literature. Methods of this 
class are necessarily slow, but have compensating advan- 
tages in economy and simplicity of operation, including 
the advantage that the sodium salt just mentioned, which 
is generally desired, can be obtained directly, without the 
need of special treatment to remove copper or silver. 
This reaction is the one employed in the improved appa- 
ratus and procedure which we describe below. 

In Salzer’s original method the phosphorus was 
immersed in water or a dilute solution of sodium chloride. 
In either case the liquid soon becomes strongly acid, and 
unless the process is interrupted rather frequently for 
renewal of the liquid and recovery of the hypophosphoric 
acid already formed, some of the acid is likely to be lost 


Tan. Chem. 211, 1. 1882. 

* Jour. Phar. et Chim., (5) 6, 123, 1882. 

* Ber. chem. Ges., 16, 749, 1883. 

* Ber. chem. Ges., 43, 2003, 1910. : 

* Salzer, loc. cit.; Bansa, Zs. anorg. chem., 6, 128, 1894; Cavalier and 
Cornec, Bull. Soe. Chim., (4) 5, 1058, 1909. 


588 Van Name and Huff— 


by hydrolytic decomposition.© Drawe’ introduced an 
important improvement by substituting for the water a 
25 per cent solution of sodium acetate. This expedient, 
by keeping the concentration of hydrogen ion low, greatly 
diminishes the rate of decomposition, so that frequent 
removal of the liquid is unnecessary, and the care of the 
apparatus is materially simplified. Still better results, 
as our own experiments have demonstrated, can be 
obtained by the use of a solution of sodium carbonate. 
Our apparatus, which is a modification of that of 
Bansa,° is shown in the accompanying figure. It consists 


Imiveie tt 


of a cylindrical glass jar, conveniently about 5 inches in 
diameter by 7 inches in height, provided with a flanged 
cover of plaster of Paris, cast to shape. ‘The phosphorus, 
in the form of cylindrical sticks, twenty or more in num- 
ber, is suspended in the liquid by glass rods, which pass 
through holes drilled at regular intervals in the cover 
and are held at the proper height by corks on the project- 
ing ends. ‘The fit of the rods in the holes is close enough 
to prevent swinging. Each rod has a small knob or 
enlargement at the lower end, and extends through the _ 
whole length of the stick of phosphorus which it supports. — 
It is imbedded in the phosphorus by melting the latter in 


° For measurements of the rate of this hydrolysis see Van Name and 
Huff, this Journal, 45, 103, 1918. 

* Ber. chem. Ges., 21, 3401, 1888. 

®° Zs. anorg. chem., 6, 128, 1894. 


Preparation of Hypophosphates. 589 


a test tube submerged in warm water, inserting the rod 
until its knob rests on the bottom of the tube, and finally 
transferring the whole to a jar of cold water, taking care 
to hold the rod in the center of the phosphorus until the 
latter has hardened. When completely cooled the stick 
of phosphorus is drawn out of the tube by a pull on the 
imbedded glass rod. In our work the sticks of phos- 
phorus were about 3-5 inches long by 0-65 inch in diameter. 

The jar is charged with about a liter of water and any 
convenient amount of sodium carbonate, usually about 
250 grams. It is immaterial whether the salt is in solu- 
tion or not. The cover and suspended sticks of phos- 
phorus are then put in place, and the corks adjusted so 
that less than one centimeter of each stick projects from 
the liquid. As the exposed area of the phosphorus grad- 
ually becomes reduced by oxidation and solution this 
adjustment has to be repeated, ordinarily at intervals 
of two or three days. Control over the rate of the reac- 
tion is maintained by regulating the access of air to the 
interior of the jar. Several extra holes in the cover are 
provided for this purpose and these are partly closed 
with stoppers to the extent necessary to give a satisfac- 
tory rate. Too high a rate is apt to result in spontaneous 
ignition and consequent melting of the exposed portion of 
some of the sticks. The apparatus should be set up in 
some cool place, such as a cellar, and shielded from drafts, 
which have a tendency to accelerate the reaction. A 
convenient way of protecting the apparatus against 
drafts and accidents is to cover it with a large bell jar, 
taking care to leave a small opening for the entrance of 
alr. 

As the oxidation proceeds any sodium carbonate which 
was still undissolved at the start passes gradually into 
solution and the alkalinity steadily decreases. From 
time to time samples of the liquid are withdrawn with a 
pipette (inserted through a special hole, usually kept 
stoppered, in the center of the cover) and tested with 
Congo Red.° When the turning point of this indicator 
is reached, the cover and suspended sticks of phosphorus 
are simply transferred to another jar of the same size, 


* Methyl Orange may be used instead of Congo Red. The hydrogen-ion 
concentration of a pure solution of acid sodium hypophosphate is slightly 
nearer to the turning point of Congo Red than to that of Methyl Orange, 
but it is doubtful whether this difference is of any importance here. 


590 Van Name and Huff—Hypophosphates. 


previously charged with water and sodium carbonate, 
thus making the process continuous. The product, acid 
sodium hypophosphate, is found in part as a crystalline 
precipitate in the first jar; the rest is recovered by con- 
centrating the mother liquor. It is purified from accom- 
panying phosphates and phosphites by simple recrystal- 
lization from hot water. 

This form of apparatus requires the minimum of atten- 
tion, and all the manipulations and adjustments are very 
easily made. Moreover, the sodium carbonate solution 
has distinct advantages over the sodium acetate which 
has been generally used in methods of this class hitherto. 
The alkalinity of the carbonate solution prevents hydrol- 
ysis, and the proper point for renewing the solution can 
be determined by a simple and easy test. The carbonate 
is also more economical, not only on account of its cheap- 
ness, but also because it eliminates waste. No more of 
the salt is used than is actually required to react with the 
phosphorus oxy-acids, while with sodium acetate, which 
liberates acetic acid, the lack of any convenient method 
for determining the end point makes it easy to err, either 
by deferring the renewal of the solution too long, thus 
permitting excessive acidity to develop, with consequent. 
loss of hypophosphate, or by interrupting the action too 
soon, which results in the loss of the unused excess of the 
sodium acetate. 

In our experiments the room temperature ranged 
between 10° and 15° C. and the yields between 10 and 16 
per cent of the theory. No marked relation between the 
average temperature and the magnitude of the yield was 
observed. A charge of 250 grams of anhydrous sodium 
carbonate lasted, as a rule, for a period of seven to ten 
days; the complete oxidation of the sticks of phosphorus 
required, on an average, eight or nine weeks. 


Mansfield—Western Phosphates of United States, 591 


Art. XXVII.— Origin of the Western Phosphates of the 
United States; by Grorce R. Mansrrevp.1 


The Western phosphate field occupies extensive areas 
in northeastern Utah, southeastern Idaho, southwestern 
Montana, and western Wyoming. Adams and Dick? 
have reported the discovery in Alberta of phosphate 
deposits similar to those in the states named. ‘The phos- 
phate rock occurs in mountainous districts where the 
stratified rocks are folded and faulted on both a large 
and a small scale and are greatly eroded. The phosphate 
beds may be regarded as having been formerly more or 
less continuous throughout the territory mentioned but 
the agencies of mountain building and erosion have 
separated the region into large and small phosphate- 
bearing areas of generally synclinal structure, between 
which the phosphate has either been removed or carried 
so far below the surface that it cannot be considered 
workable. 

Detailed studies by members of the U. S. Geological 
Survey, Department of the Interior, in parts of the West- 
ern field have led to the establishment of great phosphate 
reserves aggregating more than 2,600,000 acres of public 
land which are estimated to contain more than 5,290,000,- 
000 long tons of relatively high-grade phosphate rock. 
When these studies, which are only partial, have been 
completed it is probable that both acreage and tonnage 
figures will be considerably increased. 

Phosphate deposits have been identified at two geo- 
logical horizons, of upper Mississippian and Permian age 
respectively, but the upper Mississippian deposits, so far 
as known, are inferior in quality to the Permian deposits 
and far less extensive. The remarks which follow on the 
origin of the deposits have been prepared with special 
reference to the Permian deposits but it is thought that 
with some modifications they will apply also to the upper 
Mississippian deposits. 

The origin of the Western phosphate deposits has an 
important commercial bearing, for if they were residual 
hike those of the brown rock of Tennessee, or of second- 


* Published by permission of the Director of the U. S. Geological Survey. 
* Adams, F. D., and Dick, W. J., Discovery of phosphate of lime in the 
Rocky Mountains, Commission of Conservation, Canada, Ottawa, 1915. 


592 Mansfield—Western Phosphates of United States. 


ary origin, they might be expected to pass at compara- 
tively shallow depths into unleached low grade phosphate 
or even into phosphatic limestones. Thus the valuable 
deposits would be limited to a comparatively short dis- 
tance from the outcrop and the great body of rock under 
cover in the synclines would be valueless. Probably 
absolute certainty on this point cannot be reached without 
deep drilling. On the other hand the phosphate beds 
have been observed in many parts of the region and under 
many conditions by a number of geologists and every- 
where they appear to be true bedded deposits analogous 
to coal or limestone, retaining their thickness and quality 
over wide areas. For these reasons they are regarded 
as original sedimentary deposits and it is considered 
probable that they maintain at depth the characteristics 
displayed at the surface. Upon this assumption rest the 
estimates given for the Western field. 

The sources of the phosphoric acid and the methods 
of accumulation are to a considerable degree subjects of 
speculation, but it will perhaps be helpful to summarize 
opinions thus far advanced and to indicate the probable 
direction of solution of the problems involved. 

The first detailed accounts of the Western phosphates 
are contained in papers of Gale and Richards® and Black- 
welder.t These authors regard the phosphates as orig- 
inal marine sedimentary deposits and the first two give 
a very brief summary of the hitherto recognized sources 
of phosphorus and the means of its accumulation as 
phosphates’ through the agency of organic and physico- 
chemical processes. Because of the relative scarcity of 
organic remains in the actual phosphate beds, Richards 
and Mansfield® were inclined to place greater emphasis 
on physico-chemical than on organic sources and agencies. 

Blackwelder has contributed two important later 
papers. In the first’ he gives an interesting and sugges- 

*Gale, H. S., and Richards, R. W., Preliminary report on the phosphate 
deposits in southeastern Idaho and adjacent parts of Wyoming and Utah, 
U. 8. Geol. Survey, Bull. 430, pp. 457-535, 1910. 

* Blackwelder, Eliot, Phosphate deposits east of Ogden, Utah, U. S. Geol. 
Survey, Bull. 430, pp. 536-551, 1910. 

°Gale, H. S., and Richards, R. W., op. cit., pp. 461-462. 

° Richards, R. W., and Mansfield, G. R., Preliminary report on a portion 
one Idaho phosphate reserve, U. S. Geol. Survey, Bull. 470, pp. 376-377, 

aa eM aia Geology of the phosphate deposits northeast of 
Georgetown, Idaho, U. S. Geol. Survey, Bull. 577, p. 74, 1914. 


* Blackwelder, Eliot, The geologic role of phosphorus, this Journal, vol. 
42, pp. 285-298, 1916. ; 


Mansfield—Western Phosphates of United States. 593 


tive account of the cycle of changes undergone by phos- 
phorus from apatites through solution, assimilation by 
plants or animals, deposition on sea bottom or on land, 
accumulation into deposits, burial, deformation, and 
metamorphism back to apatites again. Many subcycles 
are included and individual atoms of phosphorus may 
have had widely different histories. In the second* he 
gives in abbreviated form, as derived from available 
literature, a view of organic accumulation, which is sub- 
stantially repeated here for reference. In the ocean 
special conditions of currents, temperature, etc., not yet 
understood, may have induced wholesale killing of 
animals over large areas and accumulation of putrefying 
matter on the sea floor in moderate and shallow depths. 
Decomposition through the agency of bacteria produced 
ammoniacal solutions which dissolved the solid calcium 
phosphate in bones, teeth, brachiopod shells, and tissues. 
Putrefactive conditions also prevented the existence of 
organisms attached to the bottom and most calcareous 
shells descending from the surface were probably dissolved 
by the abundant carbonic acid arising from decay. For 
physico-chemical reasons, already partly understood, the 
phosphatic material was quickly redeposited in the form 
of hydrous calcium carbo-phosphates, locally filling, 
inerusting, and replacing shells, teeth, bones, ete., but 
especially forming small rounded granules of colophanite 
and finally a phosphatic cement among all particles. The 
eranular texture is ascribed chiefly to physico-chemical 
conditions, such as result in oolitic greenalite, lmonite, 
aragonite, ete. After having been formed in quiet water 
some of the granules were reached by bottom-scouring 
currents and incorporated in clastic deposits and in some 
instances were strewn over eroded rock surfaces and so 
became constituents of basal conglomerates. 

The latest contributor to the origin of the Western 
phosphates is Pardee,® who is inclined to look with dis- 
favor upon the view that unusual or abundant sources 
supplied phosphates rapidly to the sea. He points to 
the existence of glacial conditions elsewhere in Permian 
times, and suggests that cool temperatures may have pre- 
vailed during the deposition of the Western phosphates. 


® Blackwelder, Eliot, Origin of the Rocky Mountain phosphate deposits, 
Bull. Geol. Soe. America, vol. 26, pp. 100-101, 1915. (Abstract.) 

* Pardee, J. T., The Garrison and Philipsburg phosphate fields, Montana, 
U. S. Geol. Survey, Bull. 640, pp. 225-228, 1917. 


594 Mansfield—Western Phosphates of United States. 


Carbon dioxide (CO,) is retained most abundantly by 
waters of low temperature and this gas is supplied not 
only from atmospheric sources but also from organic sub- 
tances that decompose in sea water or on the sea floor. 
Conditions would thus be unfavorable for the growth of 
coralline limestone or for the chemical precipitation of 
hme. Moreover, in such waters calcareous objects would 
tend to be dissolved and the formation of limestones com- 
posed of shells and skeletons of marine organisms would 
be hindered. But if the precipitation of phosphate was 
not checked that material would accumulate in relatively 
pureform. The great volume of the deposit (see tonnage 
estimates) needs no further explanation than the con- 
tinued or extensive application of the process that initi- 
ated the formation of the phosphate. 

The Western phosphates are agreed by all who have 
seen them in the field to be original marine deposits, 
analogous to those of Tunis, Algeria, England,!® and 
to the blue phosphates of Tennessee. The physiographic 
conditions of their deposition are little known but there 
are at least six lines of evidence which throw light upon 
the problem, and from which it may be possible to deduce 
a working hypothesis. 

(ay) The Fauna, according to Girty,!! is quite different: 
from Carboniferous faunas of the Mississippi Valley and 
even among western faunas has an extremely individual 
and novel facies. Thus the area of deposition, though of 
great extent, must have been separated from the main 
ocean or was more or less restricted. 

(2) Analyses of higher grade phosphate rock such as 
constitutes the main bed show generally less than 12 per 
cent $10,, Al,O,, Fe,O,, and MgO, all added together.’ 
Silica constitutes the greater part of this percentage and 
some of this may be of organic origin. It thus appears 
that detrital material from the land is largely absent 
from the deposit. This condition may be explained in 
several ways: (a) the deposit may have been laid in rela- 
tively deep water, like some of the modern oozes; or 
(b) the water of deposition, though shallow, may have 
been too far from land to receive much detritus from that 


*° Blackwelder, Eliot, op. cit., p. 294. 

“Gaby rer. eles he fauna of the phosphate beds of the Park City forma- 
tion in bie Wyoming, and Utah, U. 8. Geol. Survey, Bull. 436, p. 8, 1910. 

” Gale, H. S., and Richards, R. W., op. cit., p. 465. 


é 


Mansfield—Western Phosphates of United States, 595 


source; or (c) the lands adjacent to the waters of 
deposition were so low, through base leveling or other- 
wise, that they furnished little clastic material to the 
sea; or (d) following an earlier suggestion of Hayes.'® 
strong marine currents may have swept away the fine 
terrigenous material, leaving only the phosphatic oolites. 
The physiographic conditions changed from time to time 
during the deposition of the phosphatic shales, for beds 
of shale, sandstone, and limestone, some of which are 
more or less phosphatic, are interbedded with the more 
nearly pure phosphate. @ 

(3) The period of deposition may have been long. The 
time required for the deposition of the phosphate beds 
and the accompanying Permian strata is not known but 
some data permit suggestive comparisons. It has been 


‘stated that there is at least local unconformity at the base 


of the Phosphoria formation. This is not, however, 
regarded as indicating any great time interval. The top 
of the formation may also mark a disconformity and the 
faunal change above is very pronounced. ‘The time inter- 
val here may be large but on the other hand the faunal 
change may have been produced by the geographic 
changes of the late Permian or early Mesozoic without 
ereater lapse of time here than.elsewhere. The phos- 
phatie shales, with which are grouped some non-phos- 
phatiec or lean shales, sandstones and limestones, are 
about 150 feet thick, and of this thickness the actual beds 
of phosphate rock form only a small proportion. The 
Phosphoria formation as a whole, representing all the 
known Permian of the region, is about 500 feet thick. 
The Permian section in Kansas, according to Prosser," 
is about 2,000 feet thick; in Texas the Permian forma- 
tions are reported as 5,000 feet thick’? and in Oklahoma 
as 2,600 feet thick.1® If these various deposits may be 
regarded as occupying time intervals at all similar, it is 
obvious that the deposition of the Phosphoria formation 
of Idaho was at a much slower rate than the accumulation 


* Hayes, C. W., Tennessee phosphates, U. S. Geol. Survey, Seventeenth 
Ann.. Rept., pt. 2, p. 534, 1896. 

* Prosser, C. S., Revised classification of the upper Paleozoic formations 
of Kansas, Jour. Geology, vol. 10, pp. 703-737, 1902. 

* Cummins, W. F., ‘Report on the geology of northwestern Texas, Geol. 
Survey Texas, Second Ann. Rept., pp. 359-552 (p. 398), 1891. 

* Beede, J. W., Invertebrate paleontology of the upper Permian red beds 
of Oklahoma and the Panhandle of Texas, Kansas Univ. Sci. Bull., vol. 
f No.-o, Dp. tlsatil(p. 136); 1907. 


596 Mansfield—W estern Phosphates of United States. 


of Permian strata in the regions named farther east. It 
seems at least reasonable, therefore, to attribute the 
thickness and richness of the phosphatic strata to long- 
continued, slow deposition under conditions which 
excluded for considerable intervals of time the accumula- 
tion of terrigenous material and of carbonate of lime. 

(4) The ordinary processes of bacterial decay give rise 
to ammonium phosphate which, according to Clarke,!7 
has been experimentally shown to react upon mineral 
substances in such manner as to produce phosphates 
resembling those actually found. Blackwelder'® states 
that such experiments have been carried out by several 
investigators and that the conditions are such as may 
readily occur on the sea bottom where organic decom- 
position is in progress. Thus calcareous shells become 
phosphatized and even such organic material as exere- 
tory pellets and bits of wood are known to have been 
altered in the same way. Bones which initially contained 
about 58 per cent of tricalcium phosphate have their 
organic matter replaced by phosphatic minerals, thus 
raising the ratio to 85 per cent or more. 

(5) The oolitic texture so characteristic of much of the 
Western phosphate is doubtless closely connected with 
the origin of the rock. In a well presented discussion 
of the origin of oolites Brown'® concludes that the older 
oolitic beds of Pennsylvania were probably all originally 
laid down as beds of calcareous oolites composed of the 
mineral aragonite. This mineral being unstable under 
ordinary rock-forming conditions soon began to change. 
Where solutions carrying other substances such as silica 
or iron were present the oolites were more or less com- 
pletely replaced, as in the case of the siliceous oolites or 
of the Clinton iron ore. 

(6) Caleareous oolites are now forming at a number of 
places, notably in the region of the Florida keys and the 
Bahamas, where they have been studied by Drew”? and 

“ Clarke, F. W., The data of geochemistry, 3d ed., U. S. Geol. Survey, 
Bull. 616, p. 523, 1916. . 
* Blackwelder, Ehot, this Jour., vol. 42 (see above), p. 294. 

” Brown, T. C., Origin of .oolites and the oolitic texture in rocks, Geol. 
Soe. America Bull., vol. 25, pp. 745-780, pls. 26-28, 1914. 

*” Drew, G. H., On the precipitation of calcium carbonate in the sea by 
marine bacteria, and on the action of denitrifying bacteria in tropical and 


temperate seas, Carnegie Inst., Washington, Pub. 182. Papers from the 
Tortugas laboratory, vol. 5, pp. 9-53, 1914. 


Mansfield—W estern Phosphates of United States, 597 


Vaughan." Drew has shown that in these regions den1- 
trifying bacteria are very active and are precipitating 
enormous quantities of calcium carbonate largely in the 
form of aragonite. Vaughan shows that this chemically 
precipitated calcium carbonate forms spherulites or small 
balls, which, by accretion, may become oolitic grains of 
the usual size, or it may accumulate around a variety of 
nuclei to build such grains. He reaches the deduction 
that all marine oolites originally composed of calcium 
carbonate, of whatever geologic age, may confidently be 
attributed to this process. Drew’s studies of the distrib- 
ution of denitrifying bacteria have shown them to be most 
prevalent in the shoal waters of the tropics. Combining 
the results of Drew and Murray, Vaughan considers that 
ereat limestone formations, whether composed of organic 
or chemically precipitated calcium carbonate, were laid 
down in waters of which at least the surface temperatures 
were warm if not actually tropical. 

Among the deductions from the above data which may 
serve as a tentative working hypothesis for the origin of 
the Western phosphates may be mentioned the following: 

1. The phosphatic oolites and their matrix were prob- 
ably deposited originally as carbonate of lime in the form 
of aragonite. 

2. ‘The waters were probably shoal and of warm or 
moderate rather than of cold temperature. 

3. ‘The lands bordering the depositional area were low 
and furnished little sediment to the sea. Thus far the 
supposed depositional conditions agree with known mod- 
ern conditions in the Florida region. 

4. The phosphatization of the oolitic deposit was prob- 
ably subsequent to its deposition rather than coincident 
with it, for Drew shows that the activities of denitrifying 
bacteria reduce the nitrate content of the sea water and 
henee the growth of marine plants and of animals 
dependent upon them. Such conditions are favorable for 
the deposition of the carbonate but not of the phosphate 
of lime. 

). Cooler temperature in the waters of deposition, 
perhaps induced by changes in the character or direction 


* Vaughan, T. W., Preliminary remarks on the geology of the Bahamas, 
with special reference to the origin of the Bahaman and Floridian oolites, 
Carnegie Inst. Washington, Pub. 182. Papers from the Tortugas labora- 
tory, vol. 5, pp. 47-54, 1914. 


598 Mansfield—W estern Phosphates of United States. 


of marine currents, checked the activities of the denitri- 
fying bacteria and hence the conditions favorable for the 
formation of oolitic limestone. At the same time plant 
and animal life increased in the waters and furnished the 
decaying matter necessary for the phosphatization of the 
oolitic limestone in the general manner set forth in Black- 
welder’s account given above. Perhaps Pardee’s idea of 
glacial climate may have a bearing in this connection. 

6. The temperature change may have been sufficiently 
abrupt to cause the wholesale killing of certain marine 
animals, as suggested in Blackwelder’s account. ‘This 
would supply material for a fairly rapid phosphatization 
of the oolitic limestone. Such an assumption, however, 
is not compulsory because the phosphatic shales as a 
whole were doubtless formed slowly and there was time 
for sufficient accumulation and trituration of organic 
remains to produce the observed phosphatization before 
the moderate crustal changes that permitted the introduc- 
tion of the clastic material that buried the phosphate bed. 

7. The conditions set forth above, which were out- 
lined particularly with reference to the main phosphate 
bed, probably were repeated on a less extensive scale for 
the lesser beds. Shaly partings or minor shale beds in 
the phosphate might be explained as the result of occa- 
sional seaward drift of land-derived silts after some > 
unusual or protracted storm. 

8. The sea in which the phosphate was deposited was 
closed off on the east, south and west, but may have had 
connections with the ocean northward and northwest- 
ward, for Girty?? notes faunal resemblances traceable into 
Alaska, Asia, and eastern Kurope, and Adams and Dick?* 
report the discovery of phosphate at apparently the same 
horizon in Alberta. 

re (Gnurniy Ce cab Ol Cites 10 we 


*> Adams, F. D., and Dick, W. J., Discovery of phosphate of lime in the 
Rocky Mountains, Commission of Conservation, Canada, Ottawa, 19165. 


Winchell and Miller—Dustfall. 599 


Arr. XXVIII.—The Dustfall of March 9, 1918; by A. N. 
WINCHELL and EK. R. Mixer. 


Some of the snow which fell at Madison, Wisconsin, 
on March 9, 1918, contained sufficient foreign material to 
change its color from white to a light brown or yellow. 
It was observed under conditions which permitted a close 
study and the collection of some evidence and data 
regarding the material. It is the object of this note to 
put these data on record, and to discuss the quantity, 
nature, and probable source of the coloring matter. 

The colored snow came down at Madison in the form 
of moist snow mixed with sleet, during the passage of 
an unusually intense and fast moving cyclonic disturb- 
ance. It fell from 11:30 a. m. to 2:30 vp. m., 90th meridian 
time, but the proportion of coloring matter is believed 
to have been greater toward the end than at the begin- 
ning. The moist snow and sleet were preceded by rain, 
from 9:30 a. m. to 11:30 a. m., which froze as it fell, and 
remained as a sheet of ice about 5% inch thick on trees, 
wires, ete. The moist snow and sleet were followed by 
dry snow from 2:30 p. m. to 9:30 ep. m. Neither the ice 
nor the dry snow contained an appreciable amount of 
coloring matter. 

At the time of the storm the snow and sleet were 
observed to have a light reddish brown color, not only by 
the Weather Bureau observers, but also by others, some 
of whom called upon the Weather Bureau office for an 
explanation of the ‘‘dirty snow’’ while it was yet falling. 
The discoloration was still more easily seen after the pure 
white dry snow had begun falling and drifting into the 
depressions in the darker layer. On the second day fol- 
lowing, when the snow began melting the dust was left 
on top of the snow. 

Area of fall—The evidence obtained as to the area 
covered by the dusty snow fall is admittedly incomplete 
and inconclusive. Inquiries were sent immediately after 
the fall to a number of Weather Bureau officials in cities. 
The replies from most of these indicated that the con- 
tamination of the snow by city smoke, dust, and ashes had 
precluded any possibility of recognizing the colored 
snow. Only Mr. J. H. Spencer at Dubuque, Iowa, and 


Am. JOUR. Pia atts SERIES, Vou. XLVI, No. 274.—OcrossEr, 1918. 


600 | Winchell and Miller— 


Mr. W. J. Schnurbusch at Grand Haven, Mich., had 
noticed the peculiar character of the snow. 
Inquiries were then sent to codperative observers of 
the Weather Bureau in places remote from cities, from 
Wisconsin, eastward to Maine. The snow unfortunately 
had disappeared at many of these places by the time of 
the receipt of the inquiry, and only one-third of those to 
whom the inquiry was sent had noticed the phenomenon. 


Kies A: 


Fig. 1. Localities where dustfalls were observed, storm of March 7-10, 
1918. 


These observers were J. H. Martin, Portage, Wis., F. B. 
Hamilton, Hancock, Wis., J. Parkinson, Montello, Wis., 
Lewis Evans, Florence, Wis., John Brown, Newberry, 
in upper Michigan, and W. F. Dewey, Chelsea, Vt. The 
location of these points, where dust was observed, is 
indicated by dots on the outline map (fig. 1). 

Nature of the coloring matter.—A microscopic study of | 
the coloring matter separated from the melted snow 
shows that it consists chiefly of inorganic substances, 
but contains also some plant tissue. All of the material 
is in the form of very fine particles, so that it forms a 


The Dustfall of March 9, 1918. 601 


dust when dry. The following minerals have been recog- 
nized: feldspar, quartz, opal, limonite, hematite, horn- 
blende calcite, mica, magnetite, apatite, tourmaline, zir- 
con. There is also some cloud-like material which may 


gti Cece 


Fic. 2. Photomicrograph of dust from the dustfall at Madison, 9 March, 
1918, showing one of the diatoms. Magnified 360 diameters. 


be kaolin. From Rosiwal measurements! the proportion 
of the chief constituents has been estimated to be: 


Feldspar and quartz 65 to 75%. 

Amorphous material, including limonite, hematite, 
kaolin, opal, ete. 20 to 30%. 

All other constituents + 5%. 


The feldspar fragments are remarkable on account of 
the fact that they show no alteration whatever; they 
are as glassy clear as is the quartz. Both the quartz and 
feldspar are stained by limonite and hematite, and this 
condition seems to pervade the fragments so thoroughly 


+A. Rosiwal, Ueber geometrische Gesteinsanalyzen, Verh. k, k. Reich- 
sanstalt, Vienna, 1898, p. 143. 


602 Winchell and Miller— 


as to indicate that it is a condition of long standing. The 
feldspar shows no twinning and much of it is probably 
orthoclase, but other feldspars are not excluded. Calcite, 
hornblende, mica, etc., are present in very small amount. 
Magnetite particles were discovered by using a magnet. 

In addition to the minerals and organic material, this 
snow dust contains a considerable number of diatoms, 
one of which is shown in the photomicrograph (fig. 2). 
There seems to be more than one kind of diatom present, 
and the sizes vary, but the usual size in this dust 1s 0-006 
to 0-01 mm. in width and 0-02 to 0-035 mm. in length. They 
are roughly cigar-shaped and so small that it would 
require 750 laid end to end to measure one inch, and more 
than three billions to fill one cubic inch. The portion of 
the diatom found in the dust is the test, which is composed 
of hydrous silica, or opal, and has various very regular 
markings over its surface. 

Microscopic measurements of the size of the dust par- 
ticles show that they range from about 0-003 mm. to about 
0-1 mm., but a surprisingly large percentage falls within 
much narrower limits, namely 0-008 to 0-025 mm. . 

At our request, a mechanical analysis of the material 
was made by Professor H. W. Stewart of the Soils 
Department of the University of Wisconsin. He reports 
that the water-free weight of the sample used was 1-8268 
grams, and that it yielded the following: 


: Weight 

Separates. Size. Grams. Per cent. 
Oley, a 2a a ne ee Less than -005 mm. 0-2046 11-145 
PME kcnliaie pe ee ‘005 to -010 0:4020 22-005 
Medinm=sult =o 3. 010 to -025 1:0261 56-169 
Coarse Sly. 025 to -050 0-1094 5-988 
Very fine sand ....... OD. sto. 2 510 0:0222 1:215 
Pime sand. 10 to °-25 0:0189 1:035 
Medium*sand <3... De 1O 50 0-0106 0-580 
GOarse: Sand 2 ones ‘50 to 1:00 0:0053 0:290 
Pime eravel —.2. 22 Yess. 1:00 to 2:00 0:0197 1:078 

Total 1:8188 99-504 | 


Professor Stewart reports also that the organic con- 


stituents were allowed to distribute themselves wherever 
they would among the separates, with the result that 


The Dustfall of March 9, 1918. 603 


much, if not all of the four largest sizes consist of organic 
material, and the very fine sand includes both organic 
and inorganic matter. 

The organic constituents were so obviously plant tis- 
sue that they were submitted to Professor R. H. Dennis- 
ton of the Department of Botany, who reports that they 
include fragments of blades of grass, of leaves of clover 
or some similar legume, fibers of cotton, and fragments 
of coniferous wood, all more or less decayed, as shown by 
the presence of saprophytic fungi and their spores. The 
only inorganic material in the so-called ‘‘gravel’’ con- 
sists of white particles which effervesce with acetic acid; 
it is therefore a carbonate. 

An attempt was made to separate the constituents of 
the dust by means of a heavy solution of potassium mer- 
euric iodide. Most of the material sank in a liquid of 
specific gravity of 2-3, but the material still floating con- 
tained the same materials as the part which sank. A 
portion of the dust separated by mechanical analysis to 
the size 0-010 to 0-025 mm. was tested in the same way. 
Practically all of it floated at 2-7, less than one quarter 
of it sank at 2-6; again the two parts contained the same 
materials; the heavier seemed to contain less limonite 
stain than the other. It seems probable that submicro- 
scopic porosity modifies considerably the apparent speci- 
fic gravity of much of the dust. ~ 

It will be useful to compare the results of the mechan- 
ical analysis of this dust with similar analyses of soils, 
volcanic dust, atmospheric dust, as shown in the following 
table (p. 604). 

This comparison shows that the Madison dust has two 
peculiarities, namely, it is finer than the other dusts and 
it contains a large percentage within a small range of 
sizes. Some soils contain much larger amounts of clayey 
material (smaller than -005 mm.) than the Madison 
material, but a hasty search of the literature makes it 
clear that few, if any, soils contain as much silt; on the 
other hand shower and voleanic dust contains much less 
clay than the Madison dust. This may be explained as 
due to the fact that shower and volcanic dusts fall wholly 
through the action of gravity, while the Madison dust 
was brought down not by its own weight, but by the 

weight of the snow or rain condensed upon it. 


604 Winchell and Miller— 


Size ean 2 3 Size 


x 5 

‘005 mm. LETS CET Ses SES -004— -008 15 
‘005— 010 =22-01 ‘008— 016 141 st 
010— -025 5617 65:8 741 016- -:032 36-2 D2 
-025— -050 5:99 °032— -125 315 42:0 
‘05 — -10 1:22. 84-0. 13-2 -063— -125 78 42-0 
‘10 — -25 1-04 85 8 -125— -250 a5 ©=:10-0 
25 — -50 08 0-2 3 "25 — -d0 3:0 or 
‘ 1-0 “29 1-0 2 ‘ 1:0 2 wae 

10 -2:0 1-08 0-0 “0 10 -2:0 fe 
g9-bo 1003s 99-9 3 L002: 5999 


1. Dust from snow fall at Madison, Wis., March 9, 1918. 

2. Soil, Hays, Kansas, which is subject to blowing. EH. E. 
Free. ‘‘The Movement of Soil Material by the Wind, U. 8. Bur. 
Soils, Bulletin 68, page 168, 1911. 

3. Silt loam soil (‘‘Waukesha’’) from valley loess, Douglas 
Co., Neb., A. H. Meyer, et al., U. 8S. Bur. Soils, 15th Rept., 
De 1994, 1913. 

4. Dust from dust shower, Chicago, Ill., Feb., 1896. J. x 
Udden, The Mechanical Composition of Wind Deposits, Augus- 
tana Libr. Pub. 1 p..00, 1893; 

5. Volcanic dust which fell on snow in Norway after a recent 
eruption in Iceland. J. A. Udden, I. c., p. 36. 


No explanation is offered here for the small range of 
sizes within which such a large part of the Madison © 
dust is included, other than the remarkable sorting power 
of the wind; perhaps this is a sufficient explanation even 
as compared with the shower and voleanic dust, if the 
smaller size of the Madison dust is remembered. 

Quantity of the dust.—Several samples of the dust were 
obtained at Madison. Professor W. H. Twenhofel col- 
lected the yellow snow from one measured square yard 
of surface; A. N. Winchell obtained another sample 
amounting to 514 liters of snow water, while smaller 
amounts were gathered by HK. R. Miller and W. J. Mead. 
The residue left after evaporating the colored snow 
obtained from one square yard of surface weighed four 
grams, while the sample of 514 liters of snow water 
yielded 5:2 grams of residue which settled to the bottom, 
as well as :15 grams of black material, which floated at 
the surface or in the liquid. These two determinations 
are mutually corroborative since the second sample was 
obtained from somewhat more than one square yard of 
surface. They indicate that the residue amounted to 4:8 


The Dustfall of March 9, 1918. 605 


erams per square meter, or 4800 kilograms per square 
kilometer; in more familiar units, this amounts to more 
than 13-5 tons per square mile. Observers of the U. S. 
Weather Bureau, quoted above, report that this colored 
snow fell at least from Dubuque, Iowa, to Chelsea, Ver- 
mont, in an east-west direction, and from Madison, Wis- 
consin, to Newberry, Michigan, in a north-south direction. 
This is about 900 miles east and west, and 300 miles north 
and south as shown by the map, fig. 1, on which the 
localities are indicated at which the discolored snow was 
observed. It covered an area of at least one hundred 
thousand square miles and probably much more. There- 
fore, the total quantity of dust may be estimated as at 
least a million tons, and probably considerably more. In 
fact, it seems likely that the material was brought down 
throughout the area covered by this snow storm, and in 
that case, the quantity deposited would run into the tens 
or hundreds of millions of tons. 

Origin of the dust——While the meteorological data do 
not afford evidence as to the exact locality from which the 
dust came that was deposited at Madison, yet the possible 
field may be limited very materially by appealing to them. 

The winds near the ground can be eliminated at once, 
first, because the dust was brought down by sleet, which 
is known to be frozen rain, that is to say, rain formed in 
an upper, warmer, stratum, falls through a cold lower 
stratum and is frozen in it; and second, because the 
lower wind, traced back along its course, is found to have 
come from the northeast, blowing only over snow-covered 
ground, and the waters of Lake Michigan, during the 
time that it was under the influence of the storm, so that 
it could not have blown up soil or sand. 

In dealing with upper air currents, say from 500 to 
2000 meters above the ground, it is usually assumed by 
meteorologists, that the velocity is determined by the dis- 
tribution of pressure as observed with barometers at the 
surface, and that the direction is along the momentary 
direction of the isobar. The velocity of the wind has been 
shown by Shaw? to be a resultant of the gradient velocity 
and the storm movement in only certain types of storms, 
but for the sake of simplicity in obtaining a first approxi- 
mation, these conditions have been assumed in this case. 

eo te fluid in the atmosphere, Proc. Roy. Soc., Lond., ser. A, 94, 
p. 34-52. 


606 Winchell and Miller— 


Various formulas, and tables for obtaining the gradient 
velocity have been given by Shaw, Gold, Patterson, and 
Humphreys. The revised nomogram of Humphreys? 
has been used in obtaining the trajectories marked A and 
B in fig. 3, for the dust-bearing upper currents that 
arrived at Madison at the beginning and end of the 
observed time of the dustfall. 


PIG: 


ple Si LENIN 
ees Pea 
\ YN) . = ee SS > 
y A) L— Pgs 
x XY Ay \ Name age TOY 
RY) ARON Ww \\ \\ Za 
i NN We : 
Ni K\\\ \\ 
XK \ 


DXA 
XY 


Fig. 38. Curve C. shows path of center of storm of March 7-10, 1918. 

Curve B. shows trajectory of upper air current that arrived at Madison, 
Wis., at 11:30 a. M., March 9, when the dustfall began. 

Curve A. shows trajectory of upper air current that arrived at Madison, 
Wis., at 3:00 P. M., at end of dustfall. 

Curve D. shows conjectured trajectory of dust-bearing lower current 
ascending to upper stratum. 

Horizontal hatchures show snow-cover 7 P. M., March 4, 1918. 

NE-SW hatchures show area of rainfall during 24 hours preceding 
7 A. M., March 8, 1918. 

NE-SE hatchures show area of rainfall during 24 hours preceding 
7 A. M., March 9, 1918. 


The storm of March 7-10, 1918, was characterized by 
strong winds at the surface throughout its passage from 
Utah eastward, so that the mechanism for eroding the 
surface and carrying the dust up into the atmosphere was 


* Journal Franklin Inst., November, 1917, page 673, revised. 


The Dustfall of March 9, 1918. 607 


‘available over a wide area. The telegraphic report of 
the Weather Bureau at 7 a. m. of March 9, 1918, showed 
high winds prevailing throughout the southwest from 
the Mississippi valley to the Rocky Mountains. Among 
the higher velocities reached during the preceding night 
were 48 miles per hour at Oklahoma City, 44 at Denver,. 
44 at Wichita. On the preceding day the storm center 
was advancing through Utah and Colorado, and a region 
of steep barometric gradients and strong winds passed 
over the arid regions of Nevada, Utah, Arizona, Colorado, 
and New Mexico, a maximum velocity of 48 miles an hour 
being attained at Modena, in southwestern Utah. 

The velocities are sufficient to blow up into the air not 
only clouds of dust, but to whirl up from the ground. 
gravel of considerable size. The limit of snow cover, 
from the Snow and Ice Bulletin of the Weather Bureau 
of March 5, 1918, and the areas covered by rainfall during 
the advance of the storm are shown in fig. 3. Except in 
Colorado, and northern New Mexico, the territory sub- 
jected to high winds was not protected in any way, aside 
from the natural vegetal covering, against eroding winds. 
The reports from observers and from military camps in 
the region indicate that extraordinary duststorms pre- 
vailed and caused much discomfort. 

The microscopic study of the dust reveals several facts 
having an important bearing on its origin. First, it is 
well sorted and very fine. Both of these facts indicate 
that it has been carried a long distance in the air (accord- 
ing to the estimates of Udden a distance which may be 
a thousand miles or more). Next, the dust is charged 
with abundant limonite and hematite, although kaolin is 
not abundant and the feldspar is entirely unaltered. 
These facts indicate that the dust is a product of physical 
disintegration, and not of chemical decomposition, that 
is, it is derived from a region of very arid climate and 
not from any part of the Mississippi valley. Finally, the 
dust is dominantly composed of feldspar and quartz with 
very small amounts of other constituents. Therefore, it 
is derived from a region of siliceous feldspathic rocks, 
either granite or arkose, or a gneiss of similar composi- 
tion. Itis not derived from a region of limestone, sand- 
stone, mica schist, or basic igneous rocks. It contains far 
too little kaolin and its feldspar is too fresh to be derived 
from any ordinary shale or argillite. 


608 Winchell and Miller— 


From all these lines of evidence it is believed that the ~ 
dust came from an arid region of the southwestern part 
of this country, where siliceous feldspathic rocks are 
abundant. Such areas are common in New Mexico and 
Arizona. It is conjectured that the material was whirled 
up from the surface on March 8 in the afternoon when 
the convectional currents are most effective both in caus- 
ing rapid vertical movements, and in increasing the 
velocity of the surface air by mixture with the faster mov- 
ing upper air. During vertical ascent the horizontal 
component of velocity gradually increased, and the direc- 
‘tion gradually veered, as shown by the dotted curve D 
in fig. 3, until it coincided with the line of gradient veloc- 
ity indicated by the continuous lines A and B in fig. 3. 
The dust-bearing current then whirled around the storm 
center, in contra-clockwise direction until it arrived at 
the flank of the colder current flowing in from the east 
over the Great Lakes and the St. Lawrence valley. The 
warmer and lighter air from the southwest then rose over 
the colder and denser air from the east, and the precipi- 
tation of the moisture upon the dust particles as nuclei 
came about through the mechanical cooling of the ascend- 
ing air. The precipitated moisture was in the form of 
rain at first, but froze to sleet as it fell through the cold 
lower stratum. Higher ascent cooled the rising air below 
the freezing point, and then the snow formed that fell 
with the sleet formed lower down. ‘The pure white snow 
fell in the northwest winds, following the storm, and these 
probably came from the snow-covered land to the north 
or east. 

Conclusion.—The evidence here presented that a single 
storm may transport a million tons of rock material a 
thousand miles or more, emphasizes the importance of 
the wind as a geological agent, Water transports larger 
rock fragments, and its work is readily seen on every 
hand; air transports much finer material and its work is 
only rarely noticed at all; yet the air is constantly at 
work over a much larger surface than that covered by 
running water, and it is an open question whether the 
total work done by the air in transporting rock material 
is not of the same order of magnitude as the work of the 
same kind accomplished by water. 

It is clear that arid regions will constantly lose rock 
material by wind action and that the dust will be held by 


~ The Dustfall of March 9, 1918. 609 


moist areas which are covered by vegetation. This is a 
type of erosion which may carry material ‘‘up hill’? from 
a dry region of little elevation to a moist region of greater 
elevation. In the case here presented however, the 
material probably came from a mountainous arid region 
to an area of lower elevation. 

The soil of any region is probably derived in consider- 
able part from material transported by the wind. 

Diatoms and all sorts of plant and animal life of 
microscopic size as well as fragments of larger organisms 
may be transported long distances by the wind. 


Dr. Albert Mann, Plant Morphologist of the U. S. 
Department of Agriculture, has examined these diatoms 
and reports that they belong for the most part to the 
species Nitzschia amplhioxys (Ehr) W. S. and Navicula 
borealis Ehr, the former being a little more abundant 
than the latter, and being represented exclusively by a 
particularly minute variety. Diatoms are alge and grow 
only in water, but these two species are doubtless peculiar 
to localities where there is only the thin film of water 
which is brought up by surface tension in sphagnum bogs 
and present in damp moss on the trunks of trees, since 
their extreme minuteness enables them to live and 
multiply in such thin films of water. 


Madison, Wisconsin. 


610 White—Switch for Delicate Measurements. 


Art. XXIX.—WNote on a Umversal Switch for Delicate 
Potential Measurements; by Waurer P. Watts. 


Two years ago a description was published in this 
Journal! of a universal switch for thermoelectric and 
other delicate work. The instrument was then a combi- 
nation of two features which had only been tried sep- 
arately. One was the contact between thin leaves of 
copper with sheet celluloid insulation; the other, the 
mechanical arrangement for making the contacts simply 
and for changing the combination quickly. The actual 
instrument has now had over a year of trial; the cellu- 
loid insulation has again proved completely satisfactory ; 
the mechanical arrangement has been as convenient and 
reliable as was expected; but two modifications have 
been found advantageous, which deserve publication. 
To aid in describing them two diagrams are reproduced 
from the original article, which contains a detailed 
account of the construction. One modification concerns 
the contacts between the ‘‘auxiliary-connecting frames’’ 
and their bus bars. In the earlier apparatus. the only 
contacts were like the contacts between the thermoele- 
ment leads and their bus bar in the present one, and the 
making of these contacts evidently involves a slight 
amount of rubbing. The satisfactory performance of 
the earlier apparatus must have been promoted by this 
rubbing. The similar contacts in the present one are 
equally satisfactory. But the auxiliary-connecting con- 
tacts, which occurred between two bodies moving in the 
same straight line, required frequent cleaning. It there- 
fore seemed best to introduce a little rubbing here. This 
at once made these contacts as satisfactory as the others, 
and is by all means to be recommended. It was done by 
making the farther end of the auxiliary-connecting bus 
bar travel on an inclined plane (laid under each end of 
the rod, RB), while the sliding frames still move horizon- 
tally. Friction against the ‘‘ fixed auxiliary-connecting 
frame,’’ against which the bus bar returns, could be pro- 
vided by giving this frame a little horizontal travel, with 
a spring to press it toward the bus bar. The total travel 
of the operating rod is increased by the same amount. 

* This Journal, 41, 307, 1916. 


White—Switch for Delicate Measurements. 611 


Bien 


ap EELS: a8 a 


Locking bar 
. Thermoelement bus bars » 


soni 1 aleml 


Fic. 1. Top view and section of the universal switch, 44 full size. Full 
black shows copper; clear white, C, celluloid insulation; shaded, wood or 
metal. Each of the 8 rods, when pushed forward like the second one 
above, presses one of the wooden wedges, w, and with it two flexible flat 
copper thermoelement leads (or leads from some other unknown E.M.F.), 
against the thermoelement bus bars, which are copper strips connected to 
the measuring apparatus. At the same time the pin, P., in the rod, may 
push one of the movable auziliary-connecting frames 5c X, against the 
auxiliary bus bars, thus connecting in the set of potentiometer dials, or 
other auxiliary, which it is desired to use with that particular thermo- 
element. When P, is horizontal the fixed frame, FX, makes the connection. 
Change of combination is instantly made by rotating the rod. 


612 White—Switch for Delicate Measurements. 


The method adopted involved less change in an instru- 
ment already constructed, and is perhaps as good in any 
case. The bus bar, raised by the inclined plane in its 
backward travel, remains up as it returns to the fixed 
frame (to secure this the spring was shifted so as to exert 
a lifting action), and is then pulled down by a bell 
erank, operated by the further return of the sliding 
frame. This pulling down gives the rubbing. Motion 
is transmitted to the crank by a whiffletree attached to 
the two sliding frames, so that the return of either pulls 
down the bus bar. The arrangement was constructed in 
about 2 hours, mainly from strips of sheet brass. 

Rather thin bakelite of good insulating quality can now 
be bought ready cut into strips, so that instead of fasten- 
ing copper strips on the wooden bars by means of sheet 
celluloid, it may perhaps be more advantageous to pin 
them to bakelite which is fastened to the wood, provided, 
of course, that there is no machining of the edges of the 
strips. This construction is somewhat more robust, at 
any rate. 

Geophysical Laboratory, 


Carnegie Institution of Washington, 
Washington, D. C. 


Chemistry and Physics. 613 


SCIENTIFIC INTELLIGENCE. 


I. CyHeEemistry AND Puysics. 


1. An Apparatus for Determining :Molecular Weights and 
Hydrogen Equwalents—W. H. Cuapin of Oberlin College has 
devised an interesting method for the determination of the 
molecular weights of organic liquids whose boiling-points are 
below 90°C, and for determining the hydrogen equivalents of 
such metals as zine, aluminium, sodium and calcium. The 
method depends upon measuring the pressure produced by the 
volatilization of the liquid or by the formation of the gas, and 
since the apparatus is very simple and can be made from the 
materials usually at hand in chemical laboratories, the process 
should be very useful for lecture demonstrations and for stu- 
dents’ laboratory work. 

The apparatus consists of an ordinary distilling-flask of 600 ce. 
capacity, of which the side tube is cut off and replaced by a 
olass manometer tube with a bore of about 7 mm. and a vertical 
height of about 20 em. The manometer is charged with mer- 
cury and hangs perpendicularly at a little distance from the 
bulb of the flask, so that its position is outside of a beaker used 
in molecular weight determinations as a steam-bath. ‘The steam 
is supplied by boiling some distilled water in the bottom of the 
beaker, and the latter is supplied with a cover of sheet-zinec made 
in two parts so that it fits the lower part of the neck of the flask. 
The capacity of the flask including its neck is found by weighing 
it full of water. The average temperature of the interior of the 
flask when heated by steam is found by means of a thermometer 
placed at different levels in the bulb and the neck, with due 
allowance for their capacities. The mouth of the flask is pro- 
vided with a stopper containing a tube with a sliding rod 
extending into it from a side branch above the stopper for 
dropping in the weighed substance according to the arrange- 
ment commonly used in the Victor Meyer apparatus. The 
author has used as containers for the organic liquids experi- 
mented upon small gelatine capsules previously dried at 100° C. 
The change in level of the mercury is read by means of a celluloid 
millimeter-scale clamped to the manometer. 

For the determination of hydrogen equivalents of metals, 
weighed quantities of the latter are dropped into dilute acids, or 
in the case of sodium into absolute alcohol, at ordinary tempera- 
tures while the beaker is kept full of water for maintaining a 
constant, known temperature. It is advisable to wind copper 
wire around the pieces of zinc employed in order to facilitate 
their solution. : 

The calculations are simple, since the weights of substances, 


614 Scientific Intelligence. 


the volumes, and temperatures are known, while the pressures 


are determined.—Jour. Phys. Chem., 22, 337. H. L. W. 


2. The Detection of lodides~n the Presence of Cyanides—It 
is a well known fact that cyanides interfere with the qualitative 


test for iodides where the iodine is set free by means of an oxidiz- 


ing agent and an acid, and L. J. Curtman and C. KaurmMAan 
have recently studied the extent of this interference and have 
found that it varies with different oxidizing agents. It is very 
marked with potassium nitrite, much less so with the perman- 
ganate, while it is intermediate in the cases of hydrogen peroxide 
and chlorine water. Even under the best conditions it appears 
that the test may fail in the presence of more than about 10 
parts of cyanogen to one of iodine. Several methods have been 
used for removing cyanogen before testing for iodine, such as 


the ignition of the silver salts, which destroys the cyanide, or the 


boiling of a solution of soluble salts with an excess of acetic acid, 
which volatilizes the hydrocyanic acid, but the present authors 


advise precipitating the cyanide of cobalt, together with the 


ferrocyanide and ferricyanide, by the addition of cobalt nitrate 
solution, adding asbestos fiber, boiling for half a minute, filter- 
ing, and testing the filtrate for iodides after sufficient concen- 
tration.—Jour. Amer. Chem. Soc., 40, 914. H. L. W. 
3. The Determination of Zinc as Zinc Mercury Thiocyanate.— 
A gravimetric method based upon the precipitation of the com- 
pound ZnHg (SCN), by adding a reagent containing KSCN and 


HeCl, to weakly acid solutions of zine salts, filtering the precipi- 


tate on a Gooch crucible and weighing it after drying at 108° C., 


“was described several years ago by Lundell and Bee. The pre- 


cipitate was washed with water containing a minute quantity of 
the reagent on account of its solubility in pure water. 
GEORGE S. JAMIESON has now made a study of the method and 


-obtained results that indicate that it is very accurate, but he has 


found that the dried precipitate is anhydrous instead of con- 


‘taining a molecule of water of crystallization as supposed by the 
originators of the process. Jamieson observes that cadmium 
-cobalt, copper, bismuth and manganese compounds also give 


insoluble double thiocyanates, while nickel in small amounts and 
arsenic in large proportions do not interfere with the method. 


‘He has employed ammonium thiocyanate in the place of the 
potassium salt in the reagent with equally satisfactory results, 


and also he has applied titration with potassium iodate to the 


“precipitate, in the place of weighing it, with excellent results — 


Jour. Amer. Chem. Soc., 40, 1036. Fie Da Wa) 
4. Principles of Chemistry; by JonEu H. HimDEBRAND. 12mo, 


‘pp. 313. New York, 1818 (The Macmillan Company) .—This 
text-book has been prepared for the purpose of teaching chemical 


theories in connection with any other books dealing with the 


‘facts of the science. This separation of the two features of 


Chemistry and Physics. 615 


instruction is intended to facilitate the teacher’s individual 
preferences in regard to the order of presentation. The topics 


are clearly and simply presented, practically without the 


employment of mathematical formule. The book appears to be 
an excellent one for its intended purpose. EL, lee ave 

5. Organic Compounds of Arsenic and Antimony ; by GILBERT 
T. Morgan. 8vo, pp. 376. London, 1918 (Longmans, Green and 
Co.).—We have here an excellent account of these very numerous 
compounds, some of which, such as cacodyl and its derivatives, 
have been of great importance in the development of chemical 
theory, while others, including salvarsan, neosalvarsan, etc., have 
acquired extensive use in recent times in connection with the 
treatment of diseases due to pathogenic protozoa. The subject 
is presented chiefly from the point of view of pure chemistry, but 
the historical aspects are clearly brought out, the principles as 
well as many details of the methods of preparation are included, 
and many references are made to the toxic and medicinal prop- 
erties of the substances. An extensive bibliography arranged 
in chronological order is appended. H. L. W. 

6. Hdible Oils and Fats; by C. AinSwortH MITCHELL. 8vo, 
pp. 159. London, 1918 (Longmans, Green and Co.).—This is 
one of a series of Monographs on Industrial Chemistry edited 
by Sir Edward Thorpe. It gives a concise outline of the chem- 
ical composition and properties of the more important oils and 
fats, together with a description of the methods of extracting 
them from the crude materials and of purifying them. The 
physical and chemical methods of examining edible oils are also 
presented, the recent processes for hardening or hydrogenating 
oils are discussed, the manufacture of artificial butter is 
described, and an extensive and excellent bibliography of the 
subject is given. The subject is very well treated from a rather 
scientific point of view, so that the book is very well adapted 


for furnishing information in regard to the application of 


science to this very important field of industry. H. L. W. 

7. Scattering of Light by Dust-free Air, with Artificial Repro- 
duction of the Blue Sky—A very clear account of some recent 
qualitative experiments on the scattering of light by gas mole- 
ecules has just been published by their author, the Hon. R. J. 
Strutt. The vessel which contained the gas consisted of two 
brass tubes, each of diameter 1-5 inches, the axes of which inter- 
sected at right angles. To avoid circumlocutions we shall refer 
to the_parts of this compound tube as if its axes formed a dia- 
eram of ordinary rectangular coordinate axes. The light from 
the source (usually a hand-regulated carbon are of 12 amperes) 
passed toward the origin of coordinates (or intersection of the 
brass tubes) along the negative portion of the axis of x. It was 
first condensed by a quartz lens, then the heat rays were 
absorbed by the water in a cell having plane parallel quartz win- 


Am, Jour. Sci.—FourtH Series, Vout. XLVI, No. 274.—Octoser, 1918. 
27 


616 Scientific Intellagence. 


dows normal to the z-axis, next the light entered the xz-tube 
through a quartz window, after this it passed through the 
rectangular opening in a diaphragm inside the negative section of 
the tube, and finally it was absorbed and scattered by the opaque 
positive end of the tube. The negative portion of the y-tube 
was designed for making visual and photographic observations 
along its axis and hence it too was closed at the outer end by a 
quartz window. ‘The positive segment of the y-tube constituted 
a dark cave across the mouth of which the beam under investiga- 
tion passed. The x-tube was furnished with smaller lateral tubes 
to enable air and other gases to be pumped into, or out of, the 
tubular cross. 

The field of view always consisted of a bright ring (due to 
light scattered from the entrance to the cave-tube) which was 
usually crossed by a narrow bright band arising from light seat- 
tered by the gas molecules or by fine dust particles. With 
ordinary untreated air in the apparatus, a very bright track due 
to scattering by dust particles was observed. This track had the 
same color as the are. When air, which had been dried by phos- 
phorus pentoxide and filtered by cotton wool, was pumped into 
the apparatus and allowed to stand until the few remaining dust 
particles had settled to the walls of the vessel, the beam appeared 
fainter than in the preceding case and its color was definitely 
blue. The ring of light, of course, did not vary in tint. <A pho- 
tograph taken with an ordinary plate using only ultra-violet light 
(filter of cobalt glass and paranitrosodimethyl-aniline) shows 
the diametral band across the ring very distinctly. This is in 
striking contrast to a photograph taken with a yellow screen and 
an isochromatic plate. In the latter negative the transverse 
band is extremely faint. When the vessel was exhausted, the 
blue track disappeared, nothing remaining except the ring of dif- 
fused light. Before finishing this part of the investigation 
Strutt took the most elaborate precautions to prove that the blue 
band was not due to extremely minute dust particles. 

To test if the phenomena observed were caused by hypothetical 
fluorescence of the air, the troublesome are lamp and the ordi- 
nary camera were replaced respectively by a Westinghouse- 
Cooper-Hewitt quartz-mercury lamp and a convenient spectro- 
eraph. Two spectrograms are reproduced in the paper juxta- 
posed in register one above the other. The upper half was 
obtained with a three days’ exposure to the radiations from the 
faint blue beam, the lower, with such a length of exposure to the 
mercury lamp as gave about the same intensity as the preceding. 
for ‘‘the middle of the spectrum’’ (about »4000). The upper 
spectrum shows no signs of any constituent except the known 
mereury lines. ‘‘Thus the lateral emission is scattered light, not 
fluorescent light.’’ The maximum of intensity is shifted 
markedly toward the extreme ultra-violet in the case of the scat- 


Chemistry and Physics. 617 


tered light. The visual lines of the lamp do not appear in the 
upper photograph at all, and the far ultra-violet lines are absent 
in the lower one. This effect is of the same type as the blue color 
of the sky, and it is fully accounted for by the accepted theory. 

Similar results were obtained: with other gases. Hydrogen 
gives much less scattering than air, oxygen about the same, and 
earbon dioxide decidedly more. The scattered light was blue for 
all of these gases. Finally it was found both visually and pho- 
tographically that the light scattered by the gas molecules was 
polarized, the vibrations being transverse to the direction of 
propagation, just as theory predicts for scattering by particles 
small compared with the wave-length—Proc. Roy. Soc., 94 A, 
453, 1918. Hiss U. 

8. The Occurrence in the Solar Spectrum of the Ultra-violet 
Bands of Ammoma and of Water-vapor—A question of interest 
and importance in connection with the solar spectrum is that of 
the origin of the thousands of unidentified faint lines which were 
photographed and catalogued by Rowland and Jewell. In a 
recent paper by A. Fow.er and C. C. L. Gregory are given the 
results of an investigation which was undertaken primarily in 
order to determine whether group P in the ultra-violet region 
of the solar spectrum might not be mainly due to the presence 
of ammonia in the absorbing atmosphere of the sun. It was 
already known that ammonia exhibits a remarkable band in this 
region, having its maximum intensity at about A3360, but the 
earlier records of the component lines were found inadequate for 
comparison with the solar tables. Accordingly spectrograms were 
taken with instruments of various dispersions, ranging up to that 
of the third order of a grating of 10 feet radius of curvature, 
an are between copper electrodes in an atmosphere of ammonia 
being employed as source in the latter case. 

With regard to the spectrum of ammonia the investigators 
record the following facts. The chief ammonia band consists of 
a bright central maximum about ’3360, a secondary maximum 
about A3371, and a number of lines, which occur in groups of 
three, extending to a considerable distance in both directions. 
The lines composing the two maxima are very closely crowded 
together and have been found to be arranged in series of the 
ordinary type. The components of the triplets are widely sep- 
arated near the central maxima, but the intervals diminish 
rapidly until there is final coalescence at ’3450 toward the less 
refrangible side, and at A38287 toward the more refrangible side, 
where the lines fade out. The triplets, however, are not sym- 
metrical with respect to the central maxima, and they show 
marked peculiarities, so that they are very poorly represented by 
the formule usually employed for band spectra. 

A comparison of the lines produced by the laboratory source 
with the corresponding region of the solar spectrum shows that 


618 Scientific Intellagence. 


many of the fine Fraunhofer lines are undoubtedly due to 
ammonia. The maxima in the two spectra not only agree in 
wave-length and in relative intensity but they show identical 
patches of continuous background. There is also a consistent 
representation of the groups of: three, and of the lines composing 
the secondary maximum of the ammonia group. Of the 260 
band-lines of ammonia in the region A3450 to A3286, there are 
140 which correspond with previously unidentified faint lines 
of the solar spectrum. About 100 of the remaining lines are 
obscured by lines for which metallic origins have been found, or 
coincide with lines which are too strong in the solar spectrum to 
be assigned solely to ammonia, and the few which fail to appear 
in the sun are all of low intensity. 

In a second paper by Fowler alone it is conclusively shown that 
at least 150 lines in the region of the A3064 band may confi- 
dently be assigned exclusively to water vapor. ‘‘ Besides account- 
ing for a large number of previously unidentified solar lines, the 
identification of the water-vapour band in the solar spectrum is 
of interest as furnishing further evidence of the existence of oxy- 
gen in the sun.’’ In this connection, it may be remarked that 
the author does not discuss the lines of telluric origin.—Proc. 
Roy. Soc., 94 A, 470, 472, 1918. Ee S20; 

9. A Calendar of Leading Experiments; by WM. 8S. FRANK- 
LIN and Barry Mac Nort. Pp. vii, 210; with 107 ficures. 
South Bethlehem, 1918 (Franklin, Mace Nutt and Charles).—The 
objects of this volume are stated in the authors’ preface m the 
following words: ‘‘Primarily this book has to do with class-room 
experiments in physics. The best experiments are those that are 
homely and simple, and suggestive rather than informing.’’ 
‘‘Seeondarily this book is intended to set forth the possibilities of 
an extended course in elementary dynamics, including the 
dynamics of wave motion.’’ The text is divided into six Parts 
entitled respectively: Mechanics, Heat, Electricity and Mag- 
netism, Light, Sound, and A simple treatise on wave motion. 
The appendix contains a list of 155 experiments which, in the 
opinion of the authors, should be kept on exhibition at all times 
for the enlightenment and entertainment of visitors. In addi- 
tion to purely physical topics the book contains seven ‘‘discon- 
nected essays’’ with the following titles: ‘‘On the Study of Sci- 
ence; Operative and inoperative definitions; The side-stepping 
of mathematics; Bacon’s New Engine; The philosophy of steam 
shovels and the philosophy of living; Science and technology 
versus the humanities in education; and The Traditive Lamp, or 
the proper method of handing down the sciences to posterity.’’ 
In writing a brief notice of a new book it is appropriate, cus- 
tomary, and usually possible for the reviewer to conclude with a 
few remarks which are intended to help the reader form a pre- 
liminary estimate of the probable value to him of the text in 


Miscellaneous Intelligence. 619 


question. In so doing it is the reviewer’s duty to endeavor to 
avoid snap-shot conclusions, pet opinions, ete., and to be as 
fair and generous as possible. In the present instance, however, 
the authors have incorporated throughout the text so much 
‘*fun,’’ ‘‘biting humor,’’ and adverse criticism of other writers, 
have made so many references to, and laudatory comments con- 
eerning, their book entitled General Physics, and have introduced 
new, unnecessary terms to supplant old, universally accepted 
ones, as to make it almost impossible to form an unbiased opinion 
of the pedagogical merits of the case. In short, the reader’s 
attention is continually distracted from the clear, sound explana- 
tions by remarks which should have been given as foot-notes or 
collected in additional ‘‘essays.’’ Under these circumstances, 
two sentences that occur in the volume should be quoted; they 
are: (p.iv) ‘‘The authors are teachers, and they consider teach- 
ing to be the greatest of fun, but they never yet have been helped 
im their work by anything they have ever read concerning their 
profession.’’ (p. 98) ‘‘ Any discussion which places emphasis on 
the fact that the ‘electromagnetic’ unit of charge divided by the 
‘electrostatic’ unit of charge is equal to the square of the velocity 
of light, but which stops short of a complete elementary discus- 
sion of electromagnetic wave motion, is, In our opinion, mislead- 
ing and fantastie.’’ Et SU: 


II. MisceLLANeous ScrenTIFIC INTELLIGENCE. 


1. Journal of the Ceramic Society—This new journal, devoted 
to the arts and sciences related to the silicate industries, has been 
recently begun (Jan, 1918) under the editorship of Professor 
George H. Brown of Rutgers College. It is published monthly 
as the organ of the American Ceramic Society which was founded 
in 1899; it takes the place of the annual volume of Transactions 
previously published by the Society. The prospectus of the 
journal states that ‘‘In the American Ceramic Society, the term 
ceramic is synonymous with ‘silicate industries’ and the interests 
and activities of the Society include all branches of the clayware, 
glass and cement industries as well as enameled wares of all 
kinds and in addition other closely allied products are included, 
ehief among which are abrasives, gypsum and lime. The prod- 
ucts of the three major divisions alone (clayware, glass and 
cement) aggregate over $400,000,000 per annum.’’ 

Membership in the Society is open to anyone interested in any 
branch of the ceramic industries and application should be made 
to the Society. All members receive the Journal gratis; to non- 
members the subscription price is $6.00 per year (12 issues), 
payable to the Secretary in advance; single numbers cost sixty 
eents. L. E. Barringer (Schenectady, N. Y.) is chairman of the 
Committee on publication and the Society may be addressed at 
the publication office, 211 Church St., Easton, Pa. 


620 ; Scientific Intellagence. 


2. A Century of Science in America, with especial reference to 
the American Journal of Science, 1818-1918; edited by Epwarp 
SaLIsBuRY Dana. Pp. 420, with photogravure frontispiece of 
Benjamin Silliman, 19 half-tone portraits and facsimile of cover 
page of the first number. New Haven, Conn. (The Yale Uni- 
versity Press; price $4.00.)—This volume, which reproduces 
with important additions the July number of this Journal and is 
based in part upon the Silliman Memorial Lectures delivered at 
Yale University in May last, is now in press and will be issued 
in the near future. 

OBITUARY. 


Dr. RicHarp RatrHpun, assistant Secretary of the Smith- 
sonian Institution, died in Washington on July 16 at the age of 
sixty-six years. He was born in Buffalo on January 25, 1852, 
and studied at Cornell University with the Class of 1875. He 
was early interested in natural history and through his acquaint- 
ance with Professor Charles F. Hartt was led to accept the 
position of geologist to the Geological Commission of Brazil, 
which he occupied from 1875 to 1878. He had earlier served as 
assistant in zoology in the Boston Society of Natural History 
(1874-75) and in the summer months acted under Dr. Spencer 
F’.. Baird in connection with the work of the U. 8. Fish Commis- 
sion on the New England coast. This led to his becoming scien- | 
tific assistant to the Commission in 1878, a position which he held 
until 1896. His work was earried on at first in the Peabody 
Museum of Yale University under Professor Verrill, but in 1880 
he moved to Washington, which remained his home through the 
rest of his life. In 1897 he was appointed assistant Secretary of 
the Smithsonian Institution, and the following year he was given 
charge of the National Museum. He had a genius for executive 
work and the development of the new building of the National 
Museum as well as the essential activities of the Smithsonian 
Institution owe much to his quiet, untiring labors. An estimate 
of his scientific acquirements and contributions must be deferred 
to a later number. : 

Dr. STEPHEN FARNUM PECKHAM, the able technical chemist, 
died in Brooklyn on July 1 in his eightieth year after a pro- 
tracted illness extending over some nine years. He was educated 
at Brown University and served in the hospital department dur- 
ing the Civil War. His interest was given particularly to the 
subjects of petroleum and bitumen and to these he made import- 
ant contributions. His investigations in California, Texas, 
Oklahoma and also in Trinidad yielded valuable results. A num- 
ber of papers on these subjects have been published in the pages 
of this Journal. The mineral peckhamite from the Estherville, 
Iowa, meteorite was named after him by Dr. J. Lawrence Smith. 

SAMUEL WENDELL WILLISTON, professor of paleontology in the 
University of Chicago, died recently at the age of sixty-six years. 
A notice is deferred until a later number. 


ay 
va 
(oF a 2 


es 2 i916 a 
Shey, : 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. |] 


Art. XX X.—The Radioactwe Properties of the Mineral 
Springs of Colorado; by O. C. Lustnr. 


An investigation of the radioactivity of the numerous 
mineral springs found chiefly in the mountainous region 
of Colorado was begun in the summer of 1914. The work 
was under the auspices of the Colorado State Geological 
Survey, which had undertaken some time previously a 
study of these springs in relation to the geology of their 
surroundings and the chemical constituents of their 
waters. This previous study had provided a list of some 
200 springs, giving locations, chemical analyses, and 
considerable information of a general nature. Most of 
these springs are highly mineralized, many of them are 
very hot, and many give off large quantities of gas. The 
present study was confined chiefly to the springs on this 
list although not all of them are included. On the other 
hand some springs not on the list have been included 
when they appeared to promise results of interest. It 
was impossible for several reasons to examine all the 
known springs and there are doubtless many unknown to 
us that might well be worthy of investigation. A few 
springs are located in regions where travel was practic- 
ally impossible except on foot or on horseback. Others, 
owing to an unusually rainy summer for Colorado, were 
rendered temporarily inaccessible by damage to ‘roads 
and bridges or were covered with water or the debris of 
washouts. 

Since most of the springs are situated at distances 
varying from a mile to more than fifty miles from the 


Am. Jour. Sct.—Fourts Serirs, Vou. XLVI, No. 275.—Novemser, 1918. 
28 


622 Lester—Radvoactive Properties of the 


nearest railroad it was decided to do all traveling by 
automobile. A large box divided into convenient trays 
and compartments was built firmly into the back part of 
the machine. This held all the necessary apparatus and 
supplies for a well-equipped field laboratory and made it 
possible to use the more accurate boiling-out method 
described by Boltwood' instead of the Fontaktometer. 
Mr. J. H. V. Finney, an instructor in the department of 
Physics of the University of Colorado and a skilled auto- 
mobile driver and mechanic, acted as general assistant 
not only in the field work but also in the tests made later 
in the laboratory. Without his efficient services the work 
would not have gone so smoothly nor could so much have 
been accomplished in the comparatively brief time of one 
summer. , 

The general plan of the work was to visit each spring 
and to make tests on the spot for the immediate activity 
of both water and gas. By immediate activity is meant 
the activity of freshly collected samples. Wherever it 
was possible the gases were also tested for thorium 
emanation. Samples of water and mud or sinter (if 
any) were collected chiefly from springs showing fair to 
high activity and shipped to the laboratory at the Uni- 
versity to be tested later for dissolved or deposited radio- 
active substances. : 

The field tests occupied the whole of the summer of 
1914. A few short trips were made in the fall of 1914 and 
in the summer of 1915. Tests for activity due to salts 
dissolved in the waters or deposited in muds and sinters 
continued at various times during the winter of 1914, 
most of the summer of 1915, and for some time in 1916. 
During this time tests were made also on the immediate 
activity of waters shipped in from a number of springs 
not examined during the work in the field for reasons 
given above. 7 

To avoid loss of time in waiting for an electroscope 
contaminated by active deposit to become usable again, 
several instruments or their equivalent were necessary. 
On the other hand our carrying capacity though large was 
not unlimited nor did we wish to have the care of packing, 
repacking and of keeping in order a number of pieces of 
apparatus as delicate as the leaf system of an electro- 

1This Journal, 18, 378, 1904. 


Mineral Springs of Colorado. 623 


scope. The problem was solved by constructing a num- 
ber of ionization chambers to which could be attached in 
turn the same electroscope head and leaf. The dimen- 
sions, constants, and characteristics of these electro- 
scopes have been fully discussed in a previous paper.? 


The essential features are shown in fig. 1. I is an air- 
tight cylindrical brass ionization chamber having stop 
cocks V near the top and bottom. Altogether four such 
chambers were used, all taking the same electroscope 
head but each having its own electrode E. 

The head screws on at T and is made air-tight by the 
rubber gasket r. S is an insulation made of banker’s 
specie sealing wax. Through this passes a brass rod 

* This Journal, 44, 225, 1917. 


624 Lester—Radioactive Properties of the 


P, threaded at e for the attachment of the electrode and 
carrying on its upper end the leaf support A, which is 
firmly attached to the rod by means of a four-jawed 
friction clamp. The heavy front and back plates of the 
head, which carry small windows, are not shown in the 
figure. They are easily removed by taking out a few 
screws when it is necessary to get at the leaf system. 
A Pye telemicroscope serves to read the deflections of 
the leaf. The microscope is rigidly attached to the head 
in such a way that it can not change its focusing position 
on the leaf. C is a charging device and DB is merely 
an arrangement for protecting the leaf when traveling. 

The electroscope head inclosing the insulated leaf sys- 
tem was so carefully made that it formed an almost air- 
tight chamber. This enabled the instrument to be used 
in the open with little or no disturbance to the leaf even 
when a considerable breeze was blowing. To cut down 
the natural leak due to ionization produced by sunlight 
a strong corrugated pasteboard box with suitable open- 
ings was fitted over and around the electroscope when in 
use in the open. This box also served as a protection in 
bad weather. In the field the leaf system was charged 
negatively by means of a metal tipped celluloid ‘‘charg- 
ing rod.’’ | 

The behavior of the electroscope, often under very 
trying field conditions, was practically perfect. Even in. 
rainy weather the only trouble experienced was in keep- 
ing the charging rod dry. After standing charged for 
about half an hour the natural leak was usually between 
0-05 and 0-15 division per minute although there were a 
few occasions when it amounted to nearly 0-4 division 
per minute. 

The boiling-out apparatus for the field tests of water 
samples is shown in fig. 2. The water to be tested was 
carefully introduced into a vessel I containing caustic 
soda when necessary. This vessel has a stop cock O and 
communicates through the cock H and a three-eighths 
inch brass tube with the collecting chamber BB made of 
brass tubing two inches in diameter and ten inches long. 
The neck J is made air-tight by the rubber gasket B. 
G is a glass tube serving as a water gauge. The vessel I 
was made in three sizes with capacities of 0-5 liter, 1 liter, 
and 2 liters respectively. The two-liter vessel was used 
in most cases although there were some springs for which 


625 


To Electroscope 


‘aah SRSA 
“af 
SQ H 
a: H 
= NK 
renal 
iv 
H 
{ 
hacer 
ke 


Mineral Springs of Colorado. 
Fic. 2 


626 Lester—hadwoactive Properties of the 


the one-liter was convenient and a few for which the 
half-liter had to be used. The entire apparatus except 
the drying tube D was supported on a tall, heavy, 
ring stand with suitable clamps. Two gasoline torches 
served as sources of heat. 

The method of operation is the same as that for any 
boiling-out apparatus. Boiling hot water is poured into 
the vessel C which is then raised until BB is filled to the 
top. Next the cock A is closed, H opened and the torches 
applied to I. The water in I will boil ten minutes or 
more before enough live steam begins to collect in BB 
to force the water toward the bottom of the gauge. The 
steam passing up through the central tube serves to keep 
the waterin BB hot. After the temperature of the whole 
apparatus has risen nearly to the boiling point a touch of 
the flame on I causes the water in the gauge to descend 
quickly. With care, however, boiling can be continued as 
long as it is desirable. After the boiling is completed F 
is closed, the tube T is connected to O, and the gases in 
BB are transferred to the electroscope in the usual 
manner. 

The results on the activity of both waters and gases are 
given in Table I. The individual springs are designated 
by numbers. Those marked with an asterisk (*) were 
tested by means of samples shipped to the laboratory and 
although allowance has been made for the decay of the 
emanation from the time of collection our experience 
shows that such results are always too low. The gases 
were collected over water in glass vessels graduated 
in cubic centimeters. The apparent volumes of the gas 
samples were corrected for the pressure due to water. 
vapor and reduced to standard conditions of tempera- — 
ture and barometric pressure. 

Columns 3-6 inclusive give the activity per liter of 
freshly collected samples. Column 7 gives the results of 
a number of tests on the permanent activity of spring 
waters. These were made at the laboratory after the 


° For the locations, chemical analyses and general descriptions of these 
springs see Bulletin No. 11, Colorado State Geological Survey, in press. 

All the measurements in this table are on springs located in Colorado. 
Tests were also made on samples sent from Bajada Hot Springs, New 
Mexico, from Saratoga Springs, Wyoming, and from a spring in the Cafion 
of the Colorado River near Hite, Utah. The sample from the latter spring 
had the color of a strong solution of copper sulphate and showed the 
remarkably high radium content of 12-12 x 10—° gram per liter. 


Mineral Springs of Colorado. 627 


samples had been acidified and sealed for over a month. 
Several of the samples were lost during shipment and 
some were accidentally destroyed where they were stored 
but it is scarcely to be expected that a greater number of 
tests would change the general character of the results. 

In the column headed ‘‘Remarks’’ the letter S indi- 
cates results due to Schlundt.t The letter a means that 
the sample has been taken from a pipe or other outlet 
removed from the source, while b indicates thorium 
emanation. 

Tests for thorium emanation were made in a great 
many places where there was a sufficient flow of gas. 
No indication of thorium was found anywhere except in 
spring No. 186 in Gunnison Co. near Powderhorn post- 
office. A roughly quantitative determination, made from 
the activity curve of the combined radium and thorium 
emanation and from the activity curve of the radium 
emanation alone, gave practically the same amount of 
activity for each. This scarcity of thorium emanation 
was somewhat unexpected as monazite is found in the 
sand of most of the creek and river beds so far examined 
along the whole eastern slope of the Continental Divide. 
Similar information for the western slope is lacking but 
the probabilities are that monazite exists there also. 
Thorium-bearing ores in place are unknown anywhere in 
the region in which the springs are located. 

For testing the activity of spring deposits in the solid 
form a sensitive electroscope of the usual type was con- 
structed. The ionization chamber is a cubical brass box 
having a volume of one liter. The narrow leaf is 4 cm. 
long and with its support, insulated by a piece of amber, 
projects downward into the ionization chamber at the bot- 
tom of which is a closely fitting drawer for the introduc- 
tion of the active material. 

The instrument has a measured electrical capacity of 
1:06 em. and was standardized by means of thin films 
of U,0, made up according to the method of McCoy’ but 
following the specifications of Boltwood.® Ten standard 
films were made from some very pure uranium oxide 
kindly furnished by Professor Boltwood. In no case did 


* Jour. Phys. Chem., 18, 662, 1914. 
5 Phil. Mag., 11, 176, 1906; Jour. Amer. Chem. Soc., 27, 391, 1905. 
® This Journal, 21, 418, 1906. 


628 Lester—Radioactwe Properties 


TABLE I. 


Mache 
units per liter 


Curies Ra Em. per 
No. | Temp. liter x 10-1 
26) Water Gas 
al 11-0 PEL Sir Bie ae 
3 15-5 seo oe ere oe 
5 44.5 O-20o ie 
a ASO eee eee 27-84 
iat 20-5 TPACE eis con cis 
12 13-5 AGa Oo: Res ohne 
18} 12-0 AN Aid sb Coenen 
14 10-0 Be So A aecltois 
155 15-0 GiOS? oe ts ea 
1155 12-3 AES NS ate eee 
16 A Rete dE 6) beeline nee st 
lef 10-0 OO 2r ss sani ete 
A 12-5 7 | aay Ree De 
18 42.5 HOPS Meta he creas 
Dal: 34-6 Teche, pan eee ee 
22 LOU ea acces none 
23 15-6 Ce Osawa ree % 
#25 14-0 IQA eM eee 
26 8-5 Bye i tates Ne 
27 18-5 16-80 78-0 
28 14-5 DOD Te | eS oe 
eal 6-7 ORE OP La SS 
432 6:7 OO cic no adekeeen 
34 8-0 Wo: Gare Poe cues 
35 14-3 OMG iT kerk eck 
35 14-5 LDA aia ert tee 
36 An ane 23-2 
38 26-8 TOMO same Ao ores ee 
39 12-8 trACe is wel Cee 
#A2 9.4 dts} eee roe 
43 13-0 Oo Ne de 
45 28-3 15-04 129-5 
*47 5 di OR sence sciatic 
*48 Sots (OOH aes Fea 
*49 Say LOMO Reet Meese 
52 26-0 8-35 101-6 
52 21-0 OSGeo Bor ee cle 
53 25-0 Bie eee 
54 DEED cai cde eiees 13-74 
55 Dy (Ree et oe 19-68 
58 51-5 O28) cee 
63 HO Oia serene 27-3 
64 She eds ee «alae 0.44 
67 9.5 NONCL: 21. weeds 
69 wees 3 TOME” ee Sewers 
el: 56-5 15-14 414.0 
72 8-5 HS Ores eee 
73 16-0 S240, eee 


Water | Gas 


| 


4-06 34-98 


bowen 
cooown 


eeeee 


eeece 


none 
none 
4.09 111-8 


of the 


Perma- 
nent 
activity 
of water 
Gram Ra 
per liter | 
xa0H2 


none 


ec eee 


none 


0-197 


0-180 


a Letters given in this column are explained in the text. 


Remarks? 


Mineral Springs of Colorado. 629 


TABLE I (continued). 


| Perma- 
| Curies Ra Em, per | Mache } nent 
No. | Temp. | liter x 10-19 | units per liter | activity 


of water Remarks? 


Gram Ra 
°C | Water | Gas Water | Gas_ | per liter 


fe aehtte 
76 ee Aan eS DAO. c=? ees 61-85 none 
ce 20-5 Aaa Pak, eee Hieaes =) oe Tae 2 none 
78 35-0 2 1 an ae 1-62 
80 ied > Es GU SEs - Fase 16-29 none 
81 Ree Te | wets bata, > a Se ke trace 
82 45-0 eens UNE ee =a so Sait GeO Th Ss cates & none 
83 43-0 Sees ss cece ee 0-88 
84 17-0 POR, ath ers 1-33 
85 Sn Neen RT Nn an ts et eerie Sag ee none 
86 13-7 2: BS ae en tea Ae ho es none 
87 13-0 Gra Br tera ates eps 2, ee none 
88-1 43-0 7-53 117-0 2-03 31-6 
88-2 43-0 db) cg 53 Mee ar oe 3:10 
89 40-0 yar eae es LS ee 4.19 
90 41-6 vars | ea a ee 0-69 
91 35-5 2-78 146-10 0-75 39.45 
92 32-5 a: ee Ao 2-50 
93-1 40-0 6-81 180-15 1-84 48-63 
93-2 hale Beaeue OS ns 1:78 
94 See i ae ee OCS GH au he ey 27-02 
95 38-7 Ee a he ley 2-54 
102 18-5 MEO Red x oA 0-51 
107 10-0 47-23 164-0 12-75 44.3 none 
108 10-0 DU Steere PSO ass, tes none 
109 9.3 OO... ' ete 2-99 
a ia | 8:5 APOE. an Re 11-44 
112 9-5 Dou. swe kR Os 2A soa none 
113 8-5 38-07 131-6 10-28 35-52 trace 
1 2 an O98 ~ chi 0-26 
115 16-3 AOS saree 1-23 
ELZ 10-5 LENE eames er ie 2: 2 or heey) ee en eae a 
ELT 10-2 ZA os ego ecielen a sey eaeee Ss (eases NS) 
118 10-0 et, AN te Oa de Gas Gee aie Sar ee 2. 2 eee a 
118 15-1 oes aie ee ee eae Ss ort eat et, SS) 
119 16-0 Sees asset te 0-96 
120 13-5 none trace none trace 
120 13-7 Beaeae sh, Sata: Ao Oe ee do OO eee ee Ss 
121 HA ee IG. |: ae Pg 3-23 
124 14-0 2-35 11-49 0-63 3-10 
124 14-7 22.4 15-4 3-74 Ze Gigh aloe Lo ROE Ss 
125 ~ 12-0 ro ee Mi ne Sa COR sees none 
125 12-8 pL) eee ae HT ee oa ae cea Ss 
126 18-0 15-35 77-6 4.14 20-95 none 
126 13-0 26-7 47-0 4.49 One! Tee Ss 
127 22.3 12-07 73-15 3-26 19-75 none a 
127 aug 20-1 48-1 3-36 SUS tat are Ss 
128 15-5 ast oe a eS Rate eS none 
128 12-7 eet Patele > aie a 2 ate Tg RN es So a aE SS) 
129 14.5 2-68 16-22 0-72 4.38 none a 


630 


Lester—Radioactive Properties of the 


Temp. 


7@ 


Se eee 
Ree OU 


° WohoawpeH 


PPRHOWDO, AWHHANO, aes 
UNOMONM SCHSOSOHN: HOOAH 


WH HHH 


TABLE I (continued), 


| Guries Ra Em. per 


liter x 101° 


Mache 
units per liter 


Water Gas 
TEREORES A eek 
16-60 155-2 
47-3 205-0 
4.62 21-93 
14-0 28-8 
Peet As 19-65 
16°84 eee 
QED Se Cues pene 
4.93 262-0 
wieeer 391-5 
thACe nfo ee 
Re 656-0 
OA OS. eee 
Ma 202-2 
MD eae Petite cae tee 
GOe4 Oi i Rear 
aA! stasis ye ed 
A fea) UN cone mee are 
2 assis 334-5 
IOS AL Vesceee 
atten 152-35 
AT TY Paap eee RRO eS 
SO Oia ks ween 
G38) tees 
BS Be ae oeen ss Se 
TOME oh "pete ees 
bielvaces 6-63 
PRU ESS 26 5 Mae 
OMe 12-36 
NONC~ = “te ee 
0283 2, cae 
LAD 2 oo eee 
MOMES. yg ASR 
18-62 760-0 
MRO! Ci ceae cates 
2050: = eee 
PSO Scale metas see 
sn eee 128-5 
Bee 229.7 
41-10 112-5 
79-25 375-6 
PAU SY eerie ees = 2 
tracer = ines. 
AG Eo ie pate 
se eiatie 4.97 
We eNee 1-90 
8-75 36-2 
area 5-66 


Water 


eecee 


eeeee 


ecoecvree 


0-38 
5-03 


eoeee 


Gas 


eoeeee 


ecevees 


eee eee 


eesees 


eeeeee 


cece eee 


of water 


Perma- 
nent 
activity 


Gram Ra 
per liter 
NOE ee 


eerece 


trace 


0-091 
0-121 
0-063 
0-186 


trace 
none 
none 


Remarks? 


Mineral Springs of Colorado. 631 


TABLE I (continued). 


| Perma- 
Curies Ra Em. per Mache | nent: + 
No. | Temp. ten? 367. 1On22 units per liter | activity | 
of water | Remarks? 
| Gram Ra) 
°C Water Gas Water Gas per liter | 
| | x 10-2 | 
#200 14-0 Eg io cece Oe ZO is oun ea trace 
203 20-5 ESO soo one ener 2h eas Ae eae none 
206 20-0 GAL wat eee 0-71 
207 14-5 305-5 2725-0 82-5 735-8 trace 
208 We POSS 5 4 nein AS Ki 5 am ee a 0-28 
209 14.0 MSS Ae iy ees Sr yb SeNpini s 0.283 
210 15-5 97-03 614-8 26-2 166-0 0-233 
211 24-0 trace trace trace trace 
211 ests OSI rr eras ak OEE foe ce S 
212 Oy at Sis Se wiht ees 3-61 
212 39-5 1.2 7-9 0-21 Te ey Mra Sevens 
213 24.0 9-05 35-0 2-44 9.45 none 
213 23-8 14.3 51-5 2-39 ODD eee cl ards ee Ss 
214 2350 eee ee GBF2omy ey hese 17-08 
216 eye ee’ Psiaicie Cr miles oie 0-65 
218 15-0 13-58 60-30 3-67 16-28 none 
218 14-8 2-55 20-5 0-43 DEO tis ren. S 
222 2s SSS ee ee Eh oy a =a ee ROE 0-89 
223 13-5 Ga oi ab ate tae 0.44 
223 13-0 WOR Aiea oer. Cis iiiee Su etien wae Rie es acres S) 
224 ee PPT ail sa lect 6-91 
225 21-0 7 Cy Re 0-7 Le 
229 30-5 ay ne ee 1-01 
230 49.5 5-14 10-11 1-39 2-73 
231 SEO pat gts ache « TSB Te eres 3-25 
*232 D0 Gt ST is Rea 0-21 
*233 10-0 OrO Saree: 0-18 
234 Bee ir scies . POMIOES OFS sesh 4.26 
235 — 42.5 2-28 136-6 0-62 36-88 
236 RON ae as. TO Ol oe Gah 5-39 
237 va) aes ae MASS aren Siereke. 30-20 
238 64.0 10-69 562-0 2-89 151-7 none 
239 79-0 19-80 956-8 5-35 258-35 trace 
240 68-5 19-54 1155-0 5-29 311-8 
241 70-0 21-51 1280-0 5-81 345-6 trace 
242 71-0 27-94 ~ 1147-0 7-54 309-7 
243 59-5 12.66 690-9 3-42 186-5 
244 43.0 EG DOM. 2 ee 4.47 
245 64-0 28-57 687-5 7-71 185-6 0-083 
246 68-0 18-66 1243-5 5-04 335-5 
247 66-3" 12-62 555-0 3-41 149.85 
248° ~ 5.5 PS Sn ae ‘Sele tas Bae le are a 0-085 
249 72-0 aS as setae 0-32 
250 ean So eis nits SVG: ie mak eeu 9-77 
251 SITES anes tae te ib lee ste 15-74 
252 35-5 EY: | ae Fe ae 1-19 
*253 hia oe aes eats icles IRS Rca ae ape aria none 


*254 cae LS Oe tea ee SOS hse as. 3 none 


632 Lester—Radioactive Properties of the 


TABLE II. , 


Equiv. Act. 
No. Material grams U per 
gram x 107!° 


Grams Ra | Per gram 
~<10—" 


Fusion Solution 


12 Quartz sand and orthoclase 0.474 


12 - Sand 0-423 
13 Mud and organic matter 1-865 
27 Limonite and calcareous sinter 0.299 
27 Limonite and calcareous clay 0.141 
27 Caleareous clay 0-588 
27 Caleareous clay 0.907 none 
28 Mud and limonite 1-328 
(etl Mud and muscovite 0.251 
73-1b = Clay 16-88 8-67 
73-2b = Clay 15-11 3-62 
76b = Sulphura 8-74 1-88 
77b ~—s Clay 0-732 
77b ~~ Clay : 0-265 
108 Sand 0-349 
142 Clay 0.444 
147 Carbonaceous clay 1.245 
147 Carbonaceous clay 1.54 0-291 
150 Limonite and calcareous sinter 20:79. Vase iee ae “= gal 
150 Limonite and calcareous sinter 9-36. |) oe eee 2-07 
152 Caleareous clay 0-007 
153 Caleareous clay 0-263 
153-1 Caleareous tufa 0-527 
154 Limonite and clay 0-321 
158 Caleareous sinter 172) Sa tee eee 1-14 
175 Caleareous sinter and clay 1-14 trace 
175 Caleareous sinter and clay 0-485 
177 Tufa 1-345 
182 Limonite and clay 0-639 
182 Limonite and clay 0-855 
183 Limey clay 0.724 
183 Caleareous clay 0.449 
184 Caleareous clay 0-603 
200 Porous sinter and sulphur 0-161 
203 Yellow sinter 0-233 
203-1 Tufa 0-604 0-085 
207 Limonite and sand 0-073 trace 
207 Limonite and sand 0.273 0-125 
235 0-216 
238 Caleareous clay 0-123 
238 Caleareous clay 0.397 
238 Mud 0-057 
165 Cave incrustation, sulphura trace 
165 Rusty clay none 


a Sulphur pure enough to burn. 

b The springs 73-77 are peculiar. In addition to practically pure sulphur, 
Schlundt (J. c.) finds that part of the sinter deposited by them is about 
87 per cent barium sulphate. He also finds a sample of tufa from one 
of these springs showing 14-8 « 10-° gram Ra per gram. 


Mineral Springs of Colorado. 633 


these films weigh as much as 5 mgs. and the material was 
spread uniformly on thin sheet aluminium over a surface 
of 64sq.cm. The ten films gave an average activity per 
milligram of three divisions per minute. One division 
per minute corresponds to 2-82 « 10+ gram uranium. 

Dry samples of the materials to be examined, weighing 
roughly from 0-5 lb. to 3 lbs., were first pulverized so as 
to pass through a 100-mesh screen. Small portions of 
these were further ground with freshly distilled chloro- 
form in an agate mortar and this material was thinly 
painted with a camel’s hair brush over sheet aluminium 
of the same area as the standard films. These films 
were made much thicker, however, than the standards so 
that considerable absorption undoubtedly occurred for 
which no correction has been made. 

The activities of the deposits, muds or sediments from 
a number of the springs listed in Table I are given in 
Table IJ. It was not possible to collect such samples 
from all the springs. The samples taken were usually 
from springs which showed at least some activity in the 
water or gas. From some springs more than one sample 
was taken when the deposits appeared to differ in nature, 
color, or age. These are indicated in the table by a repe- 
tition of the spring number. 

In the column headed ‘‘material’’ will be found a classi- 
fication made by the Colorado State Geological Survey 
but no formal analysis has been attempted. Column 3 
expresses the activity as equivalent to that of so many 
erams of uranium per gram. Up to the present it has 
not been possible to do the work necessary to determine 
the exact substances to which this activity is due. Small 
portions only, even of what appeared to be calcareous 
deposits, were soluble in acids. The deposits contain 
large amounts of clay and silica and the radioactive salts 
occur generally in the form of sulphates. 

The values given in column 4 were obtained by the 
method of.fusion with mixed carbonates. The samples 
were sealed for over a month in combustion tubing and 
care was taken to avoid loss of emanation during fusion. 
Column 5 contains a few results obtained by the boiling- 
out method from complete solutions of a few grams of 
material. This of course is the ideal method for reliable 
results. However, aside from the fact that lack of time 
has prevented the use of this method in all cases, it 1s 


634 Lester—Radwoactive Properties of the 


very unlikely that results would be obtained commensu- 
rate in interest with the labor involved. 

Some work has been done on a few of the springs 
listed in Table I by other observers. Wolcott’? examined 
one spring at Glenwood Springs but his method gave 
qualitative results only. The work of Headden® on the 
Doughty Springs (Nos. 73-77) near Hotchkiss, Colorado, 
was done by the photographic method and the results 
given are also qualitative. A few of the springs at Mani- 
tou, Colorado, were examined by Shedd? and his results 
show a fair agreement with later observations consider- 
ing the lack of precision in his apparatus and the fact 
that he did not use an emanation standard. 

The most extensive previous investigation is that of 
Schlundt?® who tested a number of springs near Boulder, 
at Manitou, at Steamboat Springs, and at least one 
spring at Glenwood Springs. He used a fontactometer 
having a volume of about 15 liters. His results which 
can be identified with spring's listed in this work are also 
given in Table I and are indicated by the letter S. The 
two sets of measurements sometimes agree but often 
one of them differs by amounts ranging from about one- 
fourth to five times the other. These differences are due 
partly to the methods used, to the corrections applied, 
and partly perhaps to variations in the activity of the 
sources. An examination of the two sets of temperature 
readings indicates that changes have occurred in the con- 
dition of some of the springs. Likewise the testimony of 
local observers seems to show that springs in a rather 
closely associated group sometimes change their char- 
acter due apparently to connection by means of under- 
eround channels. The differences in the measurement of 
activity, however, appear to have no relation to these 
indicated changes. 

Considered as a whole the results given in Tables I and 
II indicate a high average activity although there are a 
few springs which are inactive. The most active waters 
show the highest radioactivity yet found in the United 
States and are surpassed by but few foreign springs. 
The greatest activity found in the. spring gases is 
exceeded in the United States by a few springs in the 


7 Biennial Report Colo. School of Mines, Appendix p. 27, 1904. 
® This Journal, 19, 297, 1905. 

* Proc. Colo. Sci. Soc., 10, 233, 1912. 

7 Loc. cit. 


Mineral Springs of Colorado. 635 


Yellowstone National Park and is approached by but two 
or three European springs. 

A careful comparison of the radioactivity measure- 
ments with the data obtained from the chemical analyses 
shows that there is no connection between radioactivity 
and any chemical property. Neither is there any con- 
nection between activity and temperature, nor between 
the activity in water or gas and that in the deposits. 
Some springs situated near each other have shown activ- 
ities of very different magnitude and again the individual 
springs of a closely associated group have shown quite 
similar activities. In the first case the waters of the 
separate springs usually had the appearance of being 
different in character but not always. 

Results similar to the foregoing have been recorded by 
many previous observers both in this country and in 
Kurope. There is a general agreement that springs from 
igneous rocks are more active than those from sedi- 
mentary rocks.1t If we take the ninety-five springs of 
Table I which show an emanation content equal to or 
greater than 10 x 107° curie per liter we find that 58 or 61 
per cent are in pre-Cambrian formations or near a pre- 
Cambrian contact; 14 or 14:7 per cent are in igneous rock 
or near igneous and sedimentary contacts; 23 or 24-2 
per cent are in sedimentaries of various formations. 
Approximately 75 per cent of the more active springs 
are thus in or near metamorphic and igneous formations. 
Some of the most active springs, however, are found in 
sedimentaries. Nos. 73-77 in the Cretaceous and Nos. 
136-139 in the Miocene are examples. 

At the beginning of this investigation it was antici- 
pated that some springs of extraordinarily high radio- 
activity would be found since Colorado contains quite 
extensive deposits of radioactive ores. This expectation, 
however, was not fulfilled. No large mineral springs 
were found in regions where radioactive ores are most 
abundant... A number of springs, often highly gaseous, 
situated not far outside such regions showed in general 
the least activity of any examined. On the other hand, 
some quite active springs such as Nos. 107-109 near 


“Since this article was written there has appeared an extensive inves- 
tigation on the Radio-activity of Archean Rocks from the Mysore State by 
Smeeth and Watson (Phil. Mag., 35, 206, 1918). All these rocks, considered 
to be of igneous origin, contain remarkably little radium. The various 
igneous magmas not only appear to contain different amounts of radium 
but the radioactive material seems to be subject to magmatic segregation. 


636 Lester—Radioactiwe Properties of the 


La Veta and No. 71 near Hartsel in South Park are in 
regions where radioactive ores occur to some extent. 
Autunite is found in the La Veta region and some Carno- 
tite in South Park. Generally speaking, however, the 
most active springs are found on both slopes of the Conti- 
nental Divide and not far from it. So far as is known 
there are no bodies of radioactive ores near them. 

In the course of this work there were found many 
groups of springs situated just at the foot or within a 
mile or two of a high mountain range the individual peaks 
of which reach elevations as high as 12,000 to 14,000 feet. 
These groups are sometimes arranged in a more or less 
definite line a mile or more in length as if along an old 
fault and again are gathered together in an irregular 
area the opposite sides of which are only a few hundred 
feet apart. In such areas springs as widely different as 
a cold soda spring and a hot sulphur spring may be found 
separated by only a few feet. These areas seem to be 
merely the common outlets for underground waters 
draining often from many square miles of high mountain- 
ous country which frequently includes formations of 
widely different age and character. of 

As to the origin of the radioactivity found in natural 
waters there seems to be a general agreement that it is 
picked up little by little during the underground flow 
from the minute amounts of radioactive matter known to 
be widely diffused through all rocks and soils. Accord- 
ing to Dienert and Guillard'? the activity arises eaxclu- 
sively from this source. They point out further that 
when water comes from great depths as in Plombieres it 
is possible to find springs very near together, coming 
from the same geological beds and having very different 
activity. The work of Schmidt and Kurz‘? indicates 
that there is no dependency of emanation content on 
depth, strength of flow, chemical properties or tempera- 
ture, but only that springs from eruptive rocks are in 
general much more active than those from sedimentaries. 

The question as to whether an underground water or 
gas collects most of its radioactive material near the out-. 
let or far removed from it, whether by gradual absorption 
from surrounding rock or by rapid absorption during a 
brief contact with more active material, does not seem to 
be answerable without more information than is usually 
known about the underground course. Mining opera- 


“Le Radium, 7, 60, 1910. 
31 Phys. Zeitschr, 7, 209, 1906. 


Mineral Springs of Colorado. 637 


tions show that quite extensive open underground water 
channels are not uncommon and it is quite evident that 
many of the hot springs flow for long distances in such 
courses. Ina water course which permits free and rapid 
flow, radium emanation could be absorbed at a great dis- 
tance and brought to the surface without losing greatly 
through disintegration. Likewise a rapid flow through a 
long underground channel could give at the outlet a very 
active water or gas which need not have encountered any 
particularly active material. In the case of slow seepage 
flows which may collect in an open channel extending only 
a short distance from the outlet or which may empty into 
the pool which forms the spring itself, most of the emana- 
tion is undoubtedly collected not far away. Even 
though such a spring should show high activity it does 
not mean necessarily that there is highly active material 
near by. The slow flow and shorter distance of travel 
are compensated by the greater area of the underground 
stream and by its intimate contact with a greater amount 
of weakly emanating material. 

The foregoing argument of course does not exclude the 
possibility of the underground flow touching very active 
substances but the presence of such material can not be 
inferred from the existence of a highly radioactive water 
or gas without other evidence. If a spring happened to 
be so situated that its waters came in contact with a mate- 
rial which could be classified as even a low grade radio- 
active ore, and further if it had the large and rapid flow 
characteristic of most of the springs examined in this 
work, it seems fairly certain that it would show an activity 
of a different order of magnitude from those recorded in 
the tables above. 

My thanks are due to Professor R. D. George, Direc- 
tor of the Colorado State Geological Survey, and to his 
assistants for help in meeting many unexpected difficul- 
ties. The Survey has also furnished important informa- 
tion regarding geological formations. 

During the work in the field courtesies were extended 
by Dr. &. B. Moore and Dr. S.C. lind of the United 
States Bureau of Mines, and by Professor L. F. Miller 
formerly of the Colorado School of Mines. 

For the drawings accompanying this paper the author 
is indebted to Mr. J. H. V. Finney. 


Hale Physical Laboratory, University of Colorado, Boulder, Colorado. 


Am. Jour. Sct.—FourtH Serius, Vou. XLVI, No. 275.—Novemser, 1918. 


2 


638 Jenkins—Spotted Lakes of Epsomite m 


Art. XXXI.—Spotted Lakes of Epsomite in Washington 
and British Columbia; by Ouar P. JeEnxKins1 


Since April, 1916, large quantities of natural epsom 
salts have been mined and shipped from the so-called 
‘¢Spotted Lakes’’—two briny lakes, one in Washington 
and one in British Columbia. These lakes are both on 
Kruger Mountain, near the international boundary, and 


Geos 


Fic. 1.—Large spotted epsomite lake in British Columbia, on Kruger 
Mountain. Photograph taken during the dry season in July, 1917. 


within a few miles of each other, north of Oroville, Wash- 
ington. The lakes have no outlets and the material 
occurs as a precipitation from the evaporation of waters 
saturated with magnesium sulphate. The mineral formed 
is epsomite, MgSO,.7H,0. 

The accompanying figures show why these lakes are 
ordinarily described as being spotted. The dark spots 
represent shallow pools of brine, immediately beneath 
which are solid rock-like masses of epsomite. The areas 
between the dark spots are white because they are dry, 


+This examination was made by the writer while engaged in work for 
the Washington State Geological Survey during the summer of 1917. 


Washington and British Columbia. 639 


and a thin film of an efflorescence of these salts which 
covers them produces this appearance. Beneath this 
white film is mud, black, foul, and treacherous, which has 
been the cause of the miring of cattle in the past. Dur- 
ing the rainy season the whole lake is covered with water, 
and then only a faint appearance of the circles is visible 
beneath the surface of the fresh water. 

The smaller of these lakes, but the one more nearly 
devoid of any other mineral matter except magnesium 


Dae 2 


Fic. 2.—Small spotted epsomite lake north of Oroville, Washington. 
See explanatory cross-section, fig. 4. 


sulphate, is in the state of Washington. It has an area 
of only four acres and a depth (determined by drilling) 
of 30 feet. It has gone by the names of Salts Lake, 
Poison Lake, Spotted Lake, and Bitter Lake. It is high 
up in the hills (1000 feet above Oroville, or 2000 feet 
above sea-level), in a little depression scooped out by 
former glacial action. it has no outlet whatever, and 
hes close to bed rock, which consists of metamorphic 
rocks, dolomites, and shales. Near by, but at a shghtly 
higher elevation, are other smaller lakes or ponds of com- 
paratively fresh water. In one of these is a deposit of 
marl, which contains-many little fresh water shells. 


640 Jenkins—S potted Lakes of Epsomite in 


The drainage of this basin region is less than half of 
a square mile, but in this area are numerous metalliferous 
mineral claims on deposits supposed to prove their value 
in copper content. The mineral deposits consist largely 
of pyrite and pyrrhotite bodies, and the presence of these, 
occurring in metamorphic magnesian rocks, suggests 
very pointedly the source and origin of the magnesium 
sulphate in the lake. 


ie, Bs 


Fie. 3—View of Oroville with Osoyoos Lake at the right, Gkanogen 
River in the foreground, and Kruger Mountain in the background, with 
arrow pointing to situation of the small epsomite lake shown in fig. 2. 


Not a vestige of visible organic life is left in this lake, 
but the black mud contains considerable decayed organic 
matter. 

In mining the epsomite, first the solid salts were dug 
out of the spots or pools and hauled away. Later, water 
was obtained from a neighboring fresh-water lake, when 
not enough was to be had in the salts lake itself, and this 
was used to dissolve out the salts from beneath the mud, 
or from the pools where it was impracticable to get all 
the salts out by digging. The water was allowed to run 
down through holes in the mud, and was taken out by 
means of little gasoline pumps, sent back again through 


* 


Washington and British Columbia. 641 


other holes and pumped out again, until finally, when 
saturated it was piped to the salts plant on the railroad, 
over two miles away. 

It was discovered, however, that the spots represented 
the base of inverted cone-shaped or cylindrical masses 
of salts, the tip of the cone being attached to a lower 
horizontal bed of solid epsomite beneath, in places as 
much as fifteen feet in thickness. This fact was import- 
ant to those working the deposit, for it was found that 


Fig. 4. 


White 
efflorescence 


as YIM 


testes SIN 
41 NY Lye 
\ SAWS 


f ° 50 feet 
tH 


Fic. 4—Hypothetical vertical cross-section to show structure of small 
epsomite lake north of Oroville, Washington. 


this bed could be tunneled into and timbered, for the over- 
lying black mud was quite impervious to water. ‘The 
epsomite in this lower bed is in the form of large clear 
colorless crystals, some of which might be measured in 
feet. Upon exposure of this material to the air, a white 
frosted surface coating 1s formed, and it loses part of the 
water of crystallization, probably becoming the mineral 
kueserite, MgSO,H.0. In time the whole mineral 
changes into this new substance. Sodium sulphate and 
other allied salts are practically absent. 

In drilling to the bottom of the lake, when first pros- 
pecting, it was found that beneath the epsomite was a 
thin layer of gypsum, and between the gypsum and the bed 
rock was a thin layer of clayey material. The drilling 
was done because it was erroneously thought that the 
lake was in the crater of a voleano, and that it would have 
great depth. 

In handling the salts at the plant, the operating com- 
pany had to separate, when necessary, the included mud 
particles from the epsomite. This was done by dissolv- 
ing, setthng, and reprecipitation from a supersaturated 
solution caused by heating, evaporating, and then cool- 
ing the clear solution. Much of the material, however, 


o.P. J. 


642 Jenkins—S potted Lakes of Epsomite wm 


needed no further attention save pulverizing and packing. 
All of it was graded and packed in such a way that it 
would not deteriorate through loss of its water of erystal- 
lization. The reprecipitated crystals were dried first 
with a great deal of care. 

The large lake, which hes in Canada, is about seventy 
acres in extent. Its depth and structure were not yet 
determined when the writer visited the place, but its sur- 
face appearance was much like that of the smaller lake. 


ng, BD. 


Fic. 5.—Same spotted lake as that in fig. 1. This photograph was taken 
after the rainy season. 


At that time the first work was being done—that of 
removal of the salts from the shallow pools. The brine 
itself in the pools was so strong that it was very heavy 
and very shmy lke the white of an egg, and had an offen- 
sive odor. ‘The work was accomplished by shoveling the 
salts into wheelbarrows, wheeling them along planks laid 
down on the mud, and dumping their contents upon 
platforms on the shore. 

The writer was told that seasonal changes, and even 
the daily changes of temperature, noticeably affect this 
lake. After the rainy season the spots are nearly hidden 
beneath the surface of the water covering. In the later 
part of the summer the brine of the lake is quite concen- 
trated and during cool nights the salts crystallize out of 
the warmer daytime solution. 


Washington and British Columbia. 643 


A peculiar form of alge grows in this larger lake near 
the surface. <A film of sodium sulphate is also present 
near the surface, which is absent in the other lake. Other 
briny lakes in this country were visited, and it was found 
that in most of these sodium sulphate predominated and 
also that extensive growth of alge was noticeable. There 
is one such sodium sulphate lake within a short distance, 
just over the hill from this large epsomite lake. In some 
of these lakes faint traces of the spotted appearance could 
be detected in the arrangement of the mud beneath the 
surface of the water. 

Discussion in regard to structure of the mineral deposit 
and to origin? and source of the material will necessarily 
have to be confined to the smaller lake in Washington, 
where the writer spent more time studying conditions. 
In this regard, let us go back to the description of this 
lake, and its surrounding territory. In addition to what 
was said, the pyrite and pyrrhotite deposits were oxidized 
to a depth of several feet from the surface to a mixture 
of iron oxides, quartz, clay, and tiny erystals of gypsum. 
Leading from these deposits to the lake were drainage 
ways, on the surface of which, in places, showed whitish 
alkali streaks. 

These facts suggest the possibility that the sulphates 
and sulphuric acid, known to form from the oxidation of 
pyrite and pyrrhotite through the action of meteoric 
water and air, acted upon the dolomite and other magne- 
sian rocks, forming magnesium sulphate, which is soluble, 
and calcium sulphate, which is much less soluble. The 
result was that the magnesium sulphate was carried to 
the lake in solution. What little calcium sulphate came 
with it was precipitated first, being less soluble, as a thin 
layer of gypsum over the sediment already deposited on 
the bottom of the lake. 

This explains the formation of the horizontal layer of 
epsomite above the gypsum. The layer of mud on top 
of the epsomite layer is accounted for by the washing 
of sediment into the lake. The fresher water allowed 
some organic life to thrive, but with the increasing salin- 
ity of the lake, due to increased aridity, the organisms 


*F. M. Handy: An investigation of the mineral deposits of northern 
Okanogan County, State College of Washington, Bulletin No. 100, Pullman, 
Wash. (Suggestion is made regarding the origin of the salts in the smaller 
lake, which coincides with the theory in the present paper.) 


644 Jenkins—S potted Lakes of Epsomiete. 


must have perished, and their decaying carbonaceous 
remains were added to the general clayey mass already 
accumulated. 

The cones appear to have been formed by the gradual 
penetration of rising solutions from the lower layer and 
by its recrystallization in this newly acquired position. 
Each crystallization of the material helped to open up, 
by its expansion on forming crystals, a larger space, until 
the surface was reached. ‘The appearance on the surface 
is that of circular bodies, or of spots when viewed from a 
distance. 

The expanding force of the crystallization of magne- 
sium sulphate is well illustrated at the salts plant. The 
operators state that at times during winter, after a 
sudden drop of temperature, a saturated solution, pass- 
ing from tank to tank in a three-inch pipe, has crystallized 
with such force of expansion as to split the pipe from end 
to end. It was also found that the crystallizing salts 
could not be kept in wooden tanks, for the percolating 
solutions would work into the cracks and, upon erystal- 
lizing, would open up the joints between the boards, caus- 
ing them to leak so that they had to be lined with metal. 

The principal uses of epsomite are in medicine, in the 
tanning industry, and in the manufacture of various com- 
pounds of magnesium. It is artificially prepared else- 
where from dolomite and magnesite, and before the 
HKuropean war it was shipped to this country as a by- 
product of the potash industry in Germany. 


State College of Washington, 
Pullman, Washington. 


Wieland—American Fossil Cycads. 645 


Arr. XX XII.—A Study of some American Fossil Cycads, 
Part VIlI2 Notes on Young Floral Structures; by 
G. R. WIELAND. 


The developing fruits of the silicified cyceadeoids 
though variable in conservation, and in the smallest 
forms merely casts with indistinct traces of cell struc- 
ture, seldom fail to show points of interest. In some 
instances the eentral cone fails of conservation, in others 
the outer disk. But usually in even the smallest casts 
the organs and tissue zones are delimited by color 
gradation with varying forms of granulation; or the 
tissues are traversed by sphenocrystic banding, often of 
much beauty. Especially the palisaded zone of inter- 
seminal scales and seed stems is from the early stages of 
growth on, a sharply outlined part of the flower bud. In 
fact young fertile organs but a fraction of a millimeter 
in length and barely visible to the unaided eye are not 
uncommon. An example is shown in American Fossil 
Cycads by the writer, Vol. II, plate 35, photograph 4 
(Carnegie Publ., No. 34). In most young fruits the 
seeds early take on highly characteristic outlines, and 
display the principal testal regions. Such seeds may not 
show cell structure, but it is instructive to find the 
forms but a few millimeters in length far sharper ribbed 
than mature seeds. Disappearance of ancestral ribbing 
is thus in evidence. 

The staminate organs, on the contrary, seldom appear 
in the earlier stages as more than a cupule-lke disk. 
Kiven in larger forms the outlines of the individual 
stamens may be indistinct; but considering their paren- 
chymatous, fugacious nature the staminate structures 
are often so well silicified, as to repay scanning with 
eare. Although the ovulate outlines appear early, the 
initial synangial growth is late. Young disks are for a 
considerable time quite devoid of synangial traces. 

With the character of conservation thus briefly recalled, 
it seems worth while to append a somewhat detailed 
description of a young bisporangiate bud found during 
the early part of the present year while studying a wedge 


*Part VII of these studies appeared in this Journal for August’ 1914 
(vol. 38, p. 117). References to the earlier parts and supplementary 
articles are there given. 


646 Wieland—American Fossu Cycads. 


of the U. S. National Museum type Cycadeoidea painei.? 
Thus far attention has been specially directed to this 
type specimen mainly because of remarkable preserva- 
tion of the vegetative structures. The trunk exemplifies 
one of the most distinctive of all branching species with 


Ties, Ws 


Fig. 1 [55]. Cycadeoidéa Painei. Drawing on photograph of the 
longitudinal section of a very young bisporangiate bud emergent between 
leaf bases. Enlarged 5 times. The arrow (D) shows the thin disk 
enclosing the central cone. The elongate receptacular cushion supports — 
the developing zone of seed stems and interseminal scales. [To the left 
there is slight displacement of leaf bases due to armor fracture. | 


*See description in American Fossil Cycads, Vol. II, p. 85. To Pro- 
fessor R. S. Bassler of the United States National Museum we are 
indebted for having the wedge on which this study depends, cut with 
care and precision. ; 


* 


Young Floral Structures. 647 


small leaf bases. There is very little suggestion of fruits 
in the outer armor, which is not deep, though well con- 
served above, as betokened by the even black color and 
rough outer surface. Below, the regularly thinner 
armor shows that excision was going on. It was accord- 
ingly an agreeable surprise to find on the radial surface 
of the trunk wedge only a few centimeters out from the 
apical bud, a small bract-enveloped fruit cut nearly in the 
longitudinal plane; and interest grew when it was seen 
that although the diameter of the ovulate cone was only 5 
millimeters the seed zone was far more developed than in 
the numerous cones where minuteness of this zone indi- 
cates the monecious condition known to occur in some 
species. 

On cutting the longitudinal section, fig. 1 [or fig. 55 of 
these studies] it was found under the microscope that the 
young disk was also clearly outlined as a thin envelope 
evenly investing the central cone inside the ramentaceous 
bracts. Study, however, depends on this single section. 
As in the case of ‘‘coal ball’’ seeds like Lagenostoma 
lomaaxi of nearly the same size as the present cone and 
its disk, so in such small isolated fruits it is oftenest the 
single section fortuitously cut which is all that can read- 
ily be secured—not the exactly median longitudinal, or 
the serial transverse sections one would so much wish. 
So, here, after the loss of saw cuts there was no further 
section of critical interest which could be cut from this 
bud. Nevertheless the section passes near enough to the 
median plane to show the general form of the ovulate 
cone and allow the inference that three or four small 
deeply stained areas between the outer disk and the apex 
of the cone are the short decurved tips of microsporo- 
phylls of the spurred Cycadeoidean type. It is also to be 
inferred that a small dome was already formed by the 
spurs; while the even thickness and smooth outlines of 
the disk indicate that neither pinnules nor synangia had 
as yet developed. Curiously enough the scalariform 
tracheids of the woody cylinder of the peduncle show 
remarkably distinct preservation at certain points, even 
extending well up into the strobilus itself. Such tissues 
have already been figured from much larger immature 
cones, being unmistakable evidence that the woody cylin- 
der of the Cycadeoids was primitively scalariform. 


648 Wieland—American Fossil Cycads. 


(See American Fossil Cycads by the author, Vol. I, fig. 
80 Db.) 


With these explanations the following measurements 
may be intelligibly read: 
Greatest length of flower and peduncle... 30+ Millimeters 


Diameter of cone, disk, and bract husk 10 ‘ 
Diameter of woody cylinder of peduncle 2 a 


Diameter vot peduncle na sheer ee 4-5 a 
Cone“and adisk= emote =... soe en ee 10 a 
Diameter: of ovulate come pa 5 ee 5 pi 
Greatest length of young seed stems .... 2 a 
Diameter ole seedestemsra a ee eee 2 oi 
Disk thickness 21 eee ate ey: See 3 s 


What light, if any, does a flower like that before us 
throw on the nature of other ancient flowers, and on 
the nature of seed or cone protecting envelopes? In the 
first place it may be adduced that some evidence has been 
found for an irregular splitting of the Cycadeoidea disk 
as it divides to form the apical dome. The flowers were 
not always symmetrically divided into some given num- 
ber of microsporophylls. Furthermore in the ovulate 
flower of moncecious forms the disk aborts. Therefore 
the first step backward to a pseudovarian envelope is 
already visible. As already emphasized,’? cone reduction 
in some of the perfect Cycadeoid flowers ending in a sin- 
gle erect seed must have occurred just as readily as in 
Conifers. The Torreya type is here instructive; and 
the staminate disk enclosing an aborted ovule in Tumboa 
indicates that the ovule as well as the disk may abort. 
Furthermore the Permo-Carboniferous Gnetopsis with 
its somewhat imperfectly fused toothed cupule enclosing 
a small group of three or four seeds, presents ancient 
generalized features worth considering in connection 
with aplosporophyllous gymnosperms. The toothed 
form of the Cycadeoid dome suggests that the Gnetop- 
sid pseudovarian covering may well have been derived 
from a fertile staminate disk, or from more or less sym- 
metrically fused leaves originally staminate.* And still 


* American Fossil Cycads, Vol. I, page 244. 

* Heer in the Flora Fossilis Arctica, Plate XV, figures as the ‘‘seed of 
a Zamites (?)’’ from Kome, ? a fruit closely associated with Cycadeous 
fronds, and exactly corresponding to the fruit of Williamsoniella, in both 
form and size. In such fruits the frond tips envelope the central cone 
like the hull of a small hickory nut, and are not decurved. They may be 
bipartite. 


Young Floral Structures. 649 


further significance attaches to Gnetopsis because one or 
more of the three or four seeds may abort, proving, if 
further proof were needed, how easily the monovarian 
condition is reached. 

It is thus seen that the known facts indicate for the 
ancient plants, especially those of Carboniferous and 
even earlier time, wide cycles of change in both bi- and 
unisexual fructification, as well as in all types of floral or 
pseudovarian envelopes. That in the course of geologic 
time cupules often resulted from the fusion of sterile 
organs, is assumed. But that reduction of a staminate 
disk a little beyond the growth stage seen in fig. 1, 
coordinately with cone reduction to the monovarian con- 
dition, would result in features such as are presented by 
ancient seed types, is a fact of extraordinary interest. 
That the fusion of a Lagenostoma-like cupule with an 
inner ovarian envelope could result in the bundle sup- 
plied outer integument of amphivascular Cycadeous 
seeds is a reasonable suggestion; and that a disk become 
sterile could also assume such a secondary function is 
just as reasonable. Moreover the change could take 
place, as geologic time goes, almost instantaneously. 
The fact that some of the largest known gymnosperm 
seeds are also the earliest and most complex ought to 
have weight with botanists who regard with doubt the 
theory of secondary and complex origin of testal struc- 
tures, and see no analogy between seed and flower. 

In any study of the origin of seed coats one of the 
oldest and best known critically important types is 
Pachytesta, represented by the two species incrassata 
and gigantea, so superbly illustrated by Brongniart in 
the closing plates of his ‘‘Graines Fossiles Silicifices.”’ 
The Pachytestas are not only amongst the oldest of 
known seeds but striking because of their great size, 
symmetric radiospermy, and highly developed amphivas- 
cularity. The inner envelope is fully as complex as that 
of various endotestal seeds; while the outer envelope is 
entirely free and has a bundle system virtually as com- 
plex as that of a cycadeoid disk. It is even apparent 
that the inner envelope exhibited some apical division. 
The bundles of both envelopes have marked development 
of scalariform tracheids, uniformly present in ancient 
seed bundles and in the Cyeadeoid peduncles and many 
ancient parent stems. 


650 Wieland—American Fossil Cycads. 


The structure of the Pachytesta vascular system is, in 
fact, much too highly developed, much too reminiscent of 
stem and leaf tracheidal organization, to permit the 
assumption of a uniformly direct evolution of spores and 
spore coats into seeds to go unchallenged. Were no 
transitions from staminate to ‘‘unessential’’ organs or 
envelopes anywhere in evidence, were fusions of fertile 
organs not such omnipresent features of flowers, and 
finally were the amphiwvascular flowers and the amphiwas- 
cular seeds less in evidence in ancient, and more frequent 
in modern times, the fusion theory of seed and flower 
would be more difficult to defend. 

But let the seed of Gnetopsis be further recalled. 
Solms, in commenting on the view that the loose apical 
tissues and the attached long feathery filaments were 
devices for both wind and water transportation, remarks 
that ‘‘we cannot grant more than this’’! Similarly 
botanists apparently find difficulty in admitting that any 
explanation or theory of the origin of seed coats can also 
have a bearing on floral organization. But a fair atten- 
tion to the facts here briefly outlined with due consid- 
eration of the structures cited, and especially their 
appearance in geologic time, emphasizes the larger truth 
that seed envelopes and floral structures are not of uni- 
formly direct origin. It must be admitted that either 
fertile or sterile pseudovarian envelopes like that of 
Gnetopsis could also arise long antecedent to the 
development of seed coats comparable to those of 
Gnetum, or Cycadeoidea, or Physostoma. And this pos- 
sibility suggests Paleozoic, not Mesozoic development of 
Angiospermous seeds and flowers. The manner in which 
essentially simple courses of change progressing more 
or less continuously in all the ancient lines, resulted in 
diverse seed and floral structures, thus comes within 
the scientific vision. 


Blake—Solving Crystal Problems. 651 


Arr. XX XIII.—Means of Solving Crystal Problems; by 
JoHN M. Brake. (Article 6.) 


In several preceding articles published in this Journal 
the writer has drawn attention to methods by which the 
measuring and description of crystals can be much facil- 
itated. It would appear that the early selection of 
methods of treating crystal problems, and subsequent too 
close adherence to the original plan, has seriously 
impeded the progress of crystal study, and at the same 
time the problems involved have been made needlessly 
complex. 

The early adoption of the theory requiring the use of 
axes and parameters has led to the almost universal 
practice of treating the planes singly and in pairs. This 
practice has had the effect of diverting attention from 
the very important relation existing between the planes 
composing a zone as well as the equally important rela- 
tion between the several zones enclosing a crystal form. 
If we make a complete change in our system of studying 
crystals, and have our work conform more especially to 
the zone point of view, we may then dispense with the 
use of axes, and can manage both rectangular and 
oblique crystals with equal facility. 

It will be noted that in article 3 in this Journal, Decem- 
ber 1916, and in articles 4 and 5 in March and May 1917, 
easy plotting-and-mechanical methods are employed 
almost entirely in place of tedious and complicated alge- 
braic work. The gnomonic projection of the crystal 
planes opens up a promising means of crystal study. 
When the planes are once plotted on the sphere for the 
purpose of projection, their relative positions will be 
rigidly held, and the whole system of planes can be 
handled as a unit by simply moving the sphere into 
new positions. We can then study the plane system of 
the erystal by making various projections of the inter- 
section points where the plane normals pierce a plane 
tangent to the sphere. 

We find certain positions of this tangent plane where 
the rows of normal piercing points lie in parallel equally 
spaced lines. It is these particular positions that yield 
interesting results. Jt will be seen later in anorthite, 
that these positions occur at right angles to the axes of 


652 Blake—Solving Crystal Problems. 


the several zones. One projection plot may have few or 
no intermediate fractional plane positions, and again 
another plot may have a general converging trend of the 
zone rows, and have many fractional plane positions, 
but notwithstanding this, we may easily trace the pres- 
ence of equal spacings. 

In the past, the axial system was applied to rectangu- 
lar forms with apparent success, and such success prob- 
ably led to the original adoption of the system of refer- 
ring the planes to axes, but we find that when we have to 
deal with oblique crystals, the axial method of referring 
the planes leads to confusion, and this indicates that the 
axial plan of reckoning the planes is not of universal 
appheation. It is altogether probable that the symbols 
of the planes as at present understood may eventually 
be replaced by an entirely different form of notation. 
Farther on, some mention will be found relating to this 
matter. 


IDiMGig le. 


We will show by means of a diagram this want of gen- 
eral adaptability of the axial system. First, we give a 
rectangular zone occurring on potassium sulphate. Fig. 
1 represents one quadrant of this zone. The angles and 
symbols for the planes are taken from Tutton’s Crys- 
tallography, 1911. The cut shows the crystal planes of 
this zone edge-on as in a cross section, and it also gives 
the direction of the planes. Lines are drawn from point 
e on the axis } leading upward to the right. These 
lines are made parallel to the plane edges, and are drawn 
for the purpose of showing the relative lengths or para- 
meters they cut off on the axes b and c, and these lengths 
are found to be in the ratio of 1, 2, and 3, which corre- 
spond correctly with the symbols 011, 021, and 031. A 
line which may be considered as a tangent line has been 


Blake—Solving Crystal Probiems. 653 


drawn on this diagram (fig. 1) parallel to b e for the 
purpose of showing its intersection with the normals, 
and the intersection points are marked by dots. It will 
be seen that the dots are equally spaced, and that the 
Spaces measured from the dots to the axis ¢ correspond 
to the above given ratios. 

We cannot manage an oblique zone by the axial plan 
with equal success. Take, for example, the oblique zone 
of epidote shown in fig. 2. The angles are taken from 
Dana’s Mineralogy 1906, and the same lettering is used 
for the planes as well as the same length is given the 
axes, which are marked off on the diagram by two finely 
dotted lines, which cut off portions of the two oblique 
axes a, and c, and should thus outline the unit oblique 
octahedron. We find, however, that neither one of these 
dotted lines comes parallel to the plane edge e or 101, or 
to the plane edge r or 101, as it should, and no other 
selection of axial lengths will bring about, simultane- 
ously, both of these parallel positions. 

The application of the tangent equal space system is 
shown on this same diagram, fig. 2. The trial tangent 
line, drawn for the purpose of this comparison, is made 
parallel to the line a b, and its intersection with the plane 
normals is shown by equally spaced dots. Thus the 
equal spacing method of managing an oblique zone works 
successfully, although two of the intersection points 
happen to be lacking in this particular case. 

We will now illustrate a part the plotting sphere can 
take in making a general study of the relations of the 
planes of the crystal. For this purpose three species of 
feldspar have been in part projected by the use of the 
sphere. | 

OrTHOCLASE iS a monoclinic potash feldspar. The 
angles given by Des Cloiseaux, together with his stereo- 
graphic projection, were used as a basis for the six 
onomonic projections shown in fig. 3. The first mem- 
ber of this series of six is based on the same prismatic 
zone that was adopted by Des Cloiseaux in his stereo- 
eraphic projection, see Min. 1862. We find on compar- 
ing the first and second members in this series of plots, 
that there is a most striking similarity of form to be 
seen in the figures developed by the normal intersections 
with the tangent planes, and to all appearance there are 
identical spacings in these two figures, except that the 


Am. Jour. Sct.—FourtH Series, Von. XLVI, No. 275.—NovemBer, 1918. 
30 


654 Blake—Solving Crystal Problems. 


Cip ce 6 ec/.ech 
ie if eb’ 
ah 


@ e ® 
bh. a be 


Ovn 
6 


dh at ’ crag 

see 5 oe os ek 

ose ya 
* eS. 

e ble tebies 
A oan, 


2 ©@ @ @ @ 
vb ah bv 


bla Qik bf, 
® e e 


g* k e es lbp 
. / Vv b's 
bere teed <5 
e 228, @ et Sue 
eh Crxpeh eh §e@ eo, ef 


o,f /@ @ d In. 


Fic. 8. Orthoclase. 


second one has a more rectangular outline. This is a 
remarkable showing when we take into account that the 
two projections were made nearly ninety degrees apart, 
and that the two similar figures result from different 
sets of normal contacts made with the two widely sep- 


in ey 
3 


Blake—Solving Crystal Problems. 655 


arated projection planes. This development of like fig- 
ures cannot be a coincidence simply, but must have a 
meaning. A further study of these orthoclase projec- 
tions will show other minor resemblances or coincidences ° 
if we take into account a difference of scale. There is, 
therefore, much connected with the relations among the 
planes in this mineral species that deserves investiga- 
tion. 

ALBITE is a tricinic species of soda feldspar. It 
yields some features of interest when tested by the pro- 
jection method. Six projections of albite have already 
been given in article 4, and to save space only two of 
those recently projected will be selected for our present 
purpose. The angles calculated by Des Cloiseaux and 
his stereographic projection were made the starting 


BGs 


Fie. 4, Albite. 


point for the present trial of the method. Seven projec- 
tions were made in this recent trial, and they were found 
to give the characteristic equal spacings. 

One of these projection trials is shown in fig. 4. It 
has the same basal zone as that used by Des Cloiseaux 
in his stereographic projection. It affords an insight 
into his system of assigning symbols, and a point of 
interest is that it gives a very compact assemblage of 
the planes. A model of albite had been cut with all of 
the planes tangent to a sphere, and therefore, this model 
gave an unbiased development to all the planes. When 
used as a test, the model showed a prism development 
in favor of the prism selected by Des Cloiseaux on 
which he based his stereographic projection and his 
indices for the planes. The figure 141 in his Mineral- 
ogy, however, showed a decided prism elongation in 
another direction, and this latter prism has been used as 


656 Blake—Solving Crystal Problems. 


a base for the projection shown in fig 5. This last selec- 
tion of prism gives the most symmetrical assemblage of 
the planes of any of the albite projections, and would 
have yielded a set of symbols nearly free from fractions 
by the axial system as used by Des Cloiseaux. It will 
be noticed that the projection fig. 5 covers the largest 
area. The contrast is shown in figures 4 and 5. 

To obtain the projection shown in fig. 5 rotate the 
upper front of the crystal downwards 116 degrees. 
This brings the hidden plane p to the front side. | 

ANORTHITE is a lime feldspar, and is a typical tri- 
clinic species. It gives an interesting series of projec- 
tions. Fig. 7 shows nine of these projections, all start- 
ing from the plane g’ and fig 8 gives six of the cross 
zones, making in all fifteen. The possibilities of addi- 
tional zones have not been exhausted, but they would 


Fic. 5. Albite. Fic. 6. Anorthite. 


take up more space, and those given will answer our 
present purpose. The members of this series of plots 
can be referred to by numbers leading from left to 
right, and thus following down each of the several 
columns. The zones are read off from left to right 
from the front side of the crystal. 

The gnomonie projection fig. 6 is made from the same 
position of the erystal that Des Cloiseaux selected for 
his stereographic projection. It will assist in picking 
out the planes by their position in the zones in the fur- 


Blake—Solving Crystal Problems. 657 


ther reduced plots. These several prism zones were 
brought in place for the corresponding projections by 
rotating the front of the crystal downwards, thus bring- 
ing them successively into position. 

It will be noted that this series contains a number of 
quite symmetrical plots, and each one of these fifteen 
plots ineludes or should include all the planes, and could 
be used for a description of the crystal. Some of the 
plane positions have been inked to make them more pro- 
minent, and to aid in tracing out the more striking of 
the equal spaced zone rows. Planes that take a promi- 
nent position in one plot may take a subordinate posi- 
tion in another, and almost invariably these subordinate 
planes, themselves, will be found to fall into zones, and 
these zones although possibly not prominent in the pro- 
jection plot, yet will be found to cross at the plane posi- 
tion selected, and these subordinate planes are conse- 
quently subject to the zone law, however complicated 
their symbols might become if assigned to them by the 
axial system of notation. 

There are several of these anorthite plots that could 
be made the basis of a new and different set of symbols 
by the axial system. There has been no well-established 
guide to follow in these cases and one author admits 
that it is generally expedient to follow after the writer 
making the first description of a species. 

If we examine the anorthite projections we find that 
the space ratio, that is, space divided by radius, varies 
with the direction taken by each projected zone, and it 
varies in the individual plots. One exception was noted 
in plots 4, 6, and 14, where the spaces measured hori- 
zontally appear to be equal: Besides the exceptions 
just mentioned, there are other points of interest to 
which attention has been drawn in this paper. In the 
previous papers, methods have been suggested by which 
the preliminary work on erystals can be more easily 
accomplished. By utilizing such means more ground 
can be worked over, and interesting and important 
features may be discovered. These points of interest, 
when given proper consideration, will tend to promote 
progress in crystal work. 

While reviewing the results brought out in these 
several gnomonic projections, as they were being devel- 
oped by the graphic methods from the plots of the 


~~ 


9) 


8 


Blake—Solving Crystal Problems. 


HIG <1, 


Fic. 8. Anorthite. 


Blake—Solving Crystal Problems. 659 


planes made on the sphere, the first impression was, 
that, since the planes were presented from a number of 
viewpoints, and as a rule all their normal intersections 
with certain tangent planes fell into equally spaced 
rows or zones, that from this fact, taken in connection 
with their several positions on the crystal, there could 
be gathered data from which it would be possible to 
make an exact determination of the angular distances 
between the planes. We would thus be on the verge of 
solving a most important crystal problem. 

As the development of the projections progresses the 
conviction grows that there must be a law that could be 
expressed or made apparent by tangents, and that this 
law may be more fundamental even than the general 
laws relating to crystal development, and that the study 
of this basic tangent law by analytical methods should 
precede the study of the laws that relate more specifi- 
eally to crystal growth. _ 

It would appear that Naumann hoped to solve all 
erystal problems by analytical geometry, but it may be 
suggested that the want of success as it would now 
appear, was due to failure at the start to fully grasp the 
meaning of a fundamental natural law upon which to 
base the analytical treatment. The existence of zones 
of planes was of course understood, but their import- 
ance as relating to crystal development was not fully 
taken into account, and the axial theory was allowed to 
take the precedence. 

Many attempts have been made since Naumann’s time 
to coordinate the results of years of work on crystals, 
and various plans have been tried without effecting a 
complete and satisfactory solution. If we can once 
take such a comprehensive view of the situation as will 
lead to the discovery of a fundamental! law which we 
have reason to believe does exist, we may then expect 
that a very complicated situation will be resolved and 
an entirely new point of view be reached. A _ basic 
law, like for example the law of gravitation, should 
admit of successful treatment by analytical methods. 
The approach of such a desirable result as the complete 
utilization of such a law, may seem far distant in view 
of the present complicated conditions and want of coor- 
dination of all the observed facts, and it is probable that 
many successive steps will have to be taken before 


660 Blake—Solving Crystal Problems. 


reaching a rational explanation of all that relates to 
erystal growth. 

A general examination and measurement of many 
crystals tends to show that each crystal form has allot- 
ted to it a limited number of planes. A gnomonie pro- 
jection of a certain crystal might appear to suggest the 
need of additional planes in order to carry out the sym- 
metry and balance. The experiment mentioned in this 
Journal, May 1915, in which crystal surfaces were 
regrown, was designed to favor the development of all 
possible planes, but this plan does not extend the limit 
to any great extent. There are various forms of hemi- 
hedrism in which certain planes are suppressed, and 
there is a probability that by means of a series of 
enomonic projections, we may get an insight into some 
of the reasons why certain planes should have the 
precedence. 

A potash alum sphere was polished and grown. ‘Two 
additional planes not. commonly noticed were thus 
developed, and when plotted, these planes harmonized 
and took their places in gnomonic projections of alum 
made on the cubic, the octahedral, and the dodecahedral 
planes. But there are planes that have been credited to 
the monometric system that would not have thus har- 
monized; but structural differences occur in different 
nonometric species, as shown for instance in the cubic 
and the octahedral cleavages, and in other ways. 

The use of the plotting sphere for locating and study- 
ing the relations of the crystal planes was adopted by 
the writer in 1864. The appearance of an article which 
was probably in the Analen der Physic und Chemie, 
which gave the gnomonie projections of sulphate of cop- 
per and datholite, that showed the equal spacing fea- 
ture, turned his attention to the importance of making 
such projections as a help in crystal study, and the 
experiment of using a plotting sphere to reduce the 
amount of preliminary work in making gnomonie pro- 
jections proved so successful even with the imperfect 
apparatus at first used, that a carefully shaped sphere 
was constructed by the writer early in 1865. This 
sphere is described in article 4. 

The first article of this series was published in 1866. 
It related to the importance of measuring complete 
crystal zones. This method of measuring was intended 


Blake—Solving Crystal Problems. 661 


to facilitate plotting on the sphere, although not so men- 
tioned in the article. At that time the new system of 
drawing which required the use of the plotting sphere 
had been brought into practical form and was employed 
in making the plan-drawing of gaylussite which was 
given in art. 5, and also the perspective drawing of the 
same species given in the same article. Some descrip- 
tions of other mineral species appeared in this Journal 
at about the same period. Then for many years it 
became necessary to discontinue the study of crystals. 
The work was resumed about a decade ago and the 
drawings and projections of albite were completed as 
given in art. 3, and later some of the earlier work has 
been reviewed and the present article, 6, includes some 
more recent observations. 

As regards plotting spheres, hollow school globes are 
now so well made from paper pulp, that the exercise of 
a little more care in perfecting their shape will make 
them excellent plotting spheres. If found necessary, 
the spherical figure could be perfected by local abra- 
sion. There may be a tendency to expand in damp 
weather, and to stick in a too-closely fitted metal equato- 
rial ring, which difficulty could probably be avoided by 
making the ring of the same material as the sphere. 

The writer is indebted to Prof. T. L. Walker’s Crys- 
tallography 1914 for an account of an equal ‘‘pace’’ 
system by Dr. Victor Goldschmidt, but in that account 
there was no mention of the use of a plotting sphere 
upon which to make approximate calculations. The 
fact that the contribution from Dr. Goldschmidt is 
along lines parallel to that of the writer, is very fortu- 
nate, as it will help to further the cause of reform in 
erystallographic methods, and when a more general 
interest 1s awakened in crystal study, we may expect 
that codperative efforts will bring about a generally 
acceptable solution of many unsolved crystal problems. 

We have endeavored in this article to give some idea 
of the usefulness of the plotting sphere in bringing to 
light points of importance which might otherwise easily 
pass unnoticed. The field for this kind of exploration 
is very large, and it has remained almost untouched. 

Observations relating to zones of planes and their 
investigation by the tangent method, lead us to antici- 
pate that important developments may be expected to 


662 Blake—Solving Crystal Problems. 


follow from the application of some form of mathema- 
tical analysis. For the present, the way is still open 
to use the means of investigation that have been 
described in these articles. 

The unequal expansion of crystals in different direc- 
tions by temperature changes will affect the crystal 
angles, and complicate plans for attaining mathemati- 
cal exactness, and this fact leads us to consider the pos- 
sibilities of critical temperatures for various companeds 
at which certain values will be reached. 

The whole problem of crystal growth has not yet 
yielded to attempts at complete explanation, and if we 
may judge by the past, it is probable that there will be a 
constant supply of material for study that will keep up 
the interest in crystals for an indefinite period. 


New Haven, Conn., 
Sept., 1918. 


Browning and Scott—Separation of Germanum, 668 


Art. XXXIV.—On the Separation of Germanum from 
Arsenic by the Distillation of the Chloride in the Pres- 
ence of a Chromate; by Puitie E. Brownine and 
SEweELi EK. Scort. 


(Contribution from the Kent Chemical Laboratory of Yale Univ.—eeciv.) 


In a recent paper from this laboratory! we described a 
modification of Buchanan’s method? for the separation of 
germanium from arsenic in which the modifications con- 
sisted of a simplified form of apparatus for the distilla- 
tion, and the substitution of potassium permanganate 
for the current of chlorine used by Buchanan. An excuse 
for the presentation of this modified method was to avoid 
the necessity of the use of chlorine gas which involved 
certain unpleasant features and a rather more elaborate 
form of apparatus than is convenient for quick qualitative 
tests. 

The object of the use of oxidizing agents in this process 
is to convert any arsenic.present into the arsenic condi- 
tion and thus prevent the formation of volatile arsenious 
chloride which would distill over with the germanium 
chloride. The present paper is a description of another 
modification in which chromic acid is used to bring about 
the oxidation. Kessler? has used the reaction between 
chromic acid and arsenious acid as the basis of a method 
for the volumetric estimation of arsenious acid and one 
of us applied the same reaction in a paper published from 
this laboratory* for the estimation of chromic acid. 

The apparatus used may be briefly described as fol- 
lows: The distillation flask consisted of a Pyrex glass 
Kirlenmeyer beaker of about 75 cm® capacity fitted with a 
two hole rubber stopper. Through one of these openings 
a bent glass tube was inserted, the other end of which 
was placed just below the surface of about 3 em’ of water 
in an ordinary test tube immersed in a beaker containing 
crushed ice or cold water to aid the condensation. 
Through the second opening in the stopper another tube 
was inserted so as to have its end about 1 em below the 
surface of the liquid to be distilled. This tube was con- 

This Journal, (4) 46, 313, 1917. 

* J. Ind. and Eng. Chem., 8, 585, 1916. 


*Pogg. Anal., 95, 204, 1855. 
* This Journal, (4) 1, 35, 1896. 


664 Browning and Scott—Separation of Germanum. 


nected through a wash bottle with a carbon dioxide 
generator, so that the gas could be used to facilitate the 
boiling of the liquid, the distillation of the volatile chlor- 
ide and finally aid in the removal of any chlorine which 
might result from the action of the hydrochloric acid upon 
the excess of chromate present. 

In this flask the material, consisting of a mixture of 
arsenious oxide and germanium oxide, was placed and in 
our experiments about 5 cm? of a 10 per cent solution of 
potassium dichromate, together with a few drops of 
sulphuric acid. This mixture was then warmed for about 
a minute when the oxide dissolved and the arsenious acid 
was oxidized to arsenic acid. About 10 cm? of strong 
hydrochloric acid was added and the distillation was 
made in a current of carbon dioxide until about one half 
of the liquid was distilled, and the current of carbon 
dioxide was continued until the liquid in the distillation 
flask was cool. 

The distillate was then tested by hydrogen sulphide to 
detect the presence of the yellow As.S,, or the white GeS.,. 
The results follow in the Table. 


TABLE I. 
Result on 
10 Strong treating 
As2O3 GeO, K.Cr.20;, HCl Water distillate 
present present present present present with H.O 
erm. erm, em? em? em? 
(1) 0-050002 ae: 5 10 No ppt 
(2) 0 2000 ce ease i) 10 ar No ppt 
(3) 205000; seen a) 5 10 an As,8. 
(Des 0 50008 = ae 5 10 As,S, 
(S\ 0 B000Rs ooo 5 10 a As,S, 
Cis: 0: 2000 ie gone. 5) 3 5 No ppt 
Che 02500 7 2. 5 6 5 No ppt 
CON te nen ees 5 5 5 No ppt 
(as pera Gate: 0:0050 5, 6 5 Ges, 
Goyer Aes 0:0005 5 10 5 - GeS, 
(11) 01000  0-0010 Mee 5 GeS, 
(12) 0:1000  0-0005 5 10 5 GeS, 


Experiments 1-7 were carried out with varying amounts 
of arsenious oxide only, to determine the amount of 
arsenic which would be oxidized by about U-5 grm. of 
potassium dichromate. It was found that ()-2500 grm. 
of arsenious oxide could be successfully oxidized by this 


Browning and Scott—Separation of Germamum, 665 


amount of that reagent. In experiments (6) and (7) 
some water and less hydrochloric acid was used without 
interfering with the oxidation. In experiment (8) 
neither arsenic nor germanium were present, the object 
being to determine the possible interfering action of 
chlorine evolved upon the test with hydrogen sulphide. 
The result was satisfactory.- In experiments (9) and 
(10) small amounts of germanium oxide were used anda - 
very satisfactory result was obtained when only 0-0005 
erms. was present. Finally in experiments (11) and (12) 
a mixture of the two oxides was treated according to the 
method and it was found that 0-0005 grm. of germanium 
oxide could be readily detected when present with 0-1 
erm. arsenious oxide. 

This reaction is also well adapted to the use of the 
simplified form of apparatus described in our previous 


paper. 
New Haven, Conn., July, 1918. 


666 Springer—Mysticocrinus. 


Art. XXX V.—On Mysticocrinus, anew genus of Silurian 
Crinoidea; by Frank Sprineer. With Plate IL. 


Among recent collections from the Laurel formation 
of Niagaran age in southern Indiana, there has appeared 
a small crinoid of wholly novel type,—one of those aber- 
rant forms which occur from time to time to perplex the 
systematist and delight the morphologist. It is an Inad- 


-unate, superficially resembling the Larviformia,. but 


departing from their general facies in having a dicyclic 
base. It would seem to be intermediate between the 
Larviformia and the Fistulata, but without any close 
connection in either group; in the composition of the cup 
it resembles the Dendrocrinidae, although wholly unlike 
them in the primitive character of the arms. In the lat- 
ter respect it is somewhat similar to Haplocrinus, which 
has extremely short, unbranched arms, as is shown by a 
specimen in my possession not yet illustrated. In calling 
this peculiar form the ‘‘mysterious crinoid’’ we have an 
appropriate designation which accords well with its 
strange characters. 


MYSTICOCRINUS nov. gen. 
(Mvotixos—mysterious; Kpivov—lily ) 

Calyx rigid, globose, contracting at the arm bases, with 
no indication of loose suture or flexibility in cup or teg- 
men (thus excluding Flexibilia). Tegmen narrow, prob- 
ably covered by a pyramid of orals as in Prsocrinus 
and Symbathocrinus. Lower brachials do not take part 
in the formation of the calyx wall, i. e., no interbrachials 
(excluding Camerata). 

Base dicyclic; IBB 3, the small plate in right postemor 
position. Radianal in “primitive position below r.post.- 
ray. Anal plate 1, large, angular distally, projecting 
above level of RR. RR 5: the right posterior one (and 
no other) compound; arm facets curved and excavated, 
not filling distal face of radials, some of them bounded by 
processes projecting between the arm bases. Arms uni- 
serial, short, composed of only a few ossicles. Anal 
opening and tegmen unknown. 


MyYSsTICOCRINUS WILSONI N. Sp. 


Calyx very small—the size of Pisocrinus; flattened 
below, strongly constricted at the arm bases. Plates 
tumid, stem circular. ; 


Springer—Mysticocrinus. 667 


Infrabasals forming a shallow saucer, externally con- 
cave; the two larger (compound) plates less than twice 
the size of the smaller right posterior plate, which is cor- 
respondingly enlarged; sutures meeting anterior, right 
anterior, and left anterior basals. Basals strongly con- 
vex, bent outwards and upwards, forming about one third 
the height of the cup; posterior basal hexagonal, wider 
than high, subangular below, truncate above; postero- 
laterals pentagonal, narrower than posterior, and antero- 
laterals still narrower. 

Radianal pentagonal, truncate above and beveling the 
right lower corner of anal; about one half as high as the 
succeeding radial. Anal plate very large, sagitteform, 
higher than wide, beveled laterally by the radianal; apex 
acuminate, rising almost to height of first secundibrachs ; 
offsets of arrow head resting upon and interlocking with 
distal margins of posterior radials. 

Radials unequal and differing in shape; angular pro- 
cesses project nearly as high as the anal between the 
arm-bases from three of the radials, viz. at one (outer) 
side of each posterior, and at both sides of the anterior 
radial, while the antero-laterals have none; each process 
has an offset like those of the anal interlocking with adja- 
cent radials. Radial facets deeply curved, occupying a 
median position except on the two posterior radials in 
which the single outer processes occupy about half the 
distal width of the plate, and the facets toward the pos- 
terior side the remaining half. Anterior radial the 
largest plate in the cup; it and the two posterior radials 
widen upwards, while the two lateral radials correspond- 
ingly diminish in width, and by reason of the absence of 
processes are shorter than the former; the right poste- 
rior radial is the smallest, although with the radianal 
added it is about equal to and slightly longer than the left 
posterior. 

Arms unequal, uniserial, branching once, and appar- 
ently very. short; the two posterior and probably the 
antertor arms have two primibrachs, while the antero- 
laterals have but one; the axillaries are followed by 
series of three or more subquadrangular brachials which 
taper gradually. Anus and tegmen unknown. Stem 
circular, axial canal unknown. 

Horizon and locality. Silurian; top of chert in Laurel 
formation. Adams Quarry near St. Paul, Indiana. 


668 Springer—M ysticocrinus. 


Two specimens of this singular form have been discov- 
ered—one the nearly perfect type here figured, which is — 
about 5 mm. in diameter, and a fragment of another one 
somewhat larger. The seven enlarged figures made 
from direct photographs furnish the evidence upon which 
the diagram of the detailed structures is constructed. 
Aside from the remarkable and unprecedented combina- 
tion of general characters, the most striking feature is 
the distribution of the processes on the anal and radial 
plates in such a way that there is an arrowhead projec- 
tion between the arm bases in every interradial area. 
The arms are preserved in three rays to what is prob- 
ably almost if not quite their full length; from their taper, 
and the manner in which they infold closely over the teg- 
men, it is doubtful if they extended farther than is 
indicated in the diagram, where the brachials which have 
been lost are represented by parallel hatching. The 
pentamerism of the calyx is remarkable for a certain reg- 
ular irregularity, yet if we leave out of consideration the 
radianal it is bilaterally.symmetric. The large anal 
plate with its angular projection distalwards recalls that 
of Lecanocrimus among the Flexibilia. : 

The specific name is given in honor of Dr. Herrick E. 
Wilson, who found the type specimen among extensive 
collections made for me in the vicinity of St. Paul, Indi- 
ana, which have yielded a number of other extremely 
interesting new forms yet to be described. 


DESCRIPTION OF PLATE II 


MYSTICOCRINUS WILSONI n. sp. (Ali figures x 8.) 


Fig. 1. Posterior view of crown, showing anal plate with its arrow-shaped 
projecting apex, and lower brachials of the two posterior arms. 


2. From left posterior radial, showing interbrachial process on left 
half of plate. 

3. Left anterior radial, without projecting processes. 

4. Anterior radial view, showing projecting process on each side. 

5. Right posterior view, showing the compound radial, with RA, fol- 
lowed by r.post.R., with projecting process on right half of 
plate. 

6. Basal view, showing the concave infrabasals. 

7. Distal view, showing the short, infolding arms. 

8. Diagram of calyx, with arms so far as preserved; missing plates 


indicated by parallel hatching. 
(Specimen here figured is in the author’s collection.) 


Am. Jour. Sci., Vol. XLVI, November, 1918. Plate Il. 


Grove Karl Gilbert. 669 


GROVE KARL GILBERT. 


The history of geology, like that of other sciences, 
affords occasional instances of an undue assumption of 
authority on the part of its eminent men, grown old in 
service: their earlier work had received so general an 
adoption that in later years they strove to impose less 
acceptable opinions upon their juniors, and came to 
regard dissent from their views as at once an error and 
an impropriety. 

Never has there lived a geologist who could with better 
right than Gilbert have assumed an authoritative attitude 
among his fellows, for it has been well said of his work: 
‘*Tt is doubtful whether the product of any other geolo- 
gist of our day will escape revision at the hands of future 
research to a degree equal to the writings of Grove Karl 
Gilbert’’; yet never was there a geologist to whom an 
assumption of authority would have been more unnatural, 
or the wish to occupy a dictatorial position more remote. 
It was from no personal claim or urgency that his opin- 
ions found acceptance, but from the convincing logic 
with which they were set forth. It was his habit in pre- 
senting a conclusion to expose it as a bail might be held 
on his hand—not clutched as if to prevent its fall, not 
erasped as if to hurl it against an objector, but poised 
on the open palm, free to roll off if any breath of dis- 
turbing evidence should displace it; yet there it would 
rest in satisfied stability. Not he but the facts that he 
marshalled clamored for the adoption of the explanation 
that he had found for them. 

Fortunately for the rest of us, Gilbert gave a clear 
account of this way of studying a field problem in an 
address on ‘‘The Inculeation of Scientific Method by 
Example,’’ which he delivered as president of the Society 
of American Naturalists in 1885.1. The problem chosen 
for treatment was the deformation of the Bonneville 
shorelines, part of a larger problem upon which he had 
been éngaged for some years. The deformation of the 
shorelines is briefly set forth, and several alternative 
hypotheses proposed for its explanation are discussed 
at some length. Thus it is shown how observation is 
followed by induction, or the empirical grouping of 
discovered facts in accord with their conspicuously com- 
mon characters; how hypothetical explanations are 
invented one after the other; how each explanation must 

See this JouRNAL, 22, 284-299, 1886. 


Am. Jour. Sct.—Fourts Series, Vou. XLVI, No. 275.—Novemser, 1918. 
; 31 


eS ee 


—— 


Se EE EE SS 


670 Grove Karl Gilbert. 


be submitted to impartial tests, the tests being pro- 
vided by comparing the ‘‘deduced consequents’’ of the 
hypotheses with the appropriate facts; and how the 
hypotheses which are found to be unsuccessful by 
the inability of their ‘‘consequents’’ to match the facts 
must be set aside as failures. There was truly nothing 
new in the mental processes of this analytical method, 
for its abstract equivalent is to be found in various 
treatises on logic; the merit of the address lay in the 
presentation of the logical processes as the successive 
steps of an actual and by no means elementary problem; 
and on this account it should still be studied by every 
young geologist, for in the thirty years since its pub- 
heation no better illustration of scientific method has 
appeared. : , 

But for our present purpose the address is of value as 
a revelation of its author’s calm and unprejudiced way of 
thinking. The problems of the Great Basin and all other 
problems that Gilbert attacked were treated in the impar- 
tial manner that this address sets forth; and that fine 
quality of impartiality was not so generally to be found 
in geological discussions thirty or forty years ago as it is 
to-day. It may be well believed that Gilbert’s influence, 
not only through this address but still more through his 
personal contact with the then rising generation of geol- 
ogists, counted for much in bringing about the improving 
change. 

It would be profitable, were it possible, to trace out the 
beginning and the development of the scientific habit of 
thought in Gilbert’s mind. The beginning can hardly 
have been a paternal inheritance, nor can the develop- 
ment have been opened through paternal influence, for 
his father was an artist of moderate ability and limited. 
means in Rochester, N. Y., where Gilbert was born on 
May 6, 1843. He finished his high school course there in 
1858, and was graduated in 1862 from the University of 
Rochester, where he had taken the classical course. He 
is remembered by his companions, to whom he was known 
as ‘‘Karl,’’ as a quiet and modest boy, with a gentle dis- 
position, a lively sense of fun, pleasant manners, and a 
very even temper; he was a good student but indifferent 
to college honors.* The boy thus foreshadowed the man. 

The thirty-five study units of his college course in- 
cluded eight of mathematics, six of Latin and seven of 


* Prof. H. L. Fairchild of Rochester has kindly communicated these details . 
regarding Gilbert’s early years. 


Grove Karl Gilbert. 671 


Greek; both the ancient languages were continued into 
his senior year. Rhetoric, logic and zoology each had 
two units; and nine other subjects, including French, 
German, and geology, but one each. The extended train- 
ing in mathematics, for which young Gilbert had a 
natural capacity, served him well in certain geophysical 
researches of later years; perhaps his classical studies 
contributed to the clear style of his reports, as they seem 
also to have determined a tendency to the use of long 
words of Greek origin and occasionally to the invention 
of such words; but they did not prevent his later adop- 
tion of simplified spelling, which in his case as in so 
many others was evidently a matter of temperament, not 
of learning. 

Gilbert’s instructor in zoology and geoiogy was Henry 
A. Ward, who came to be widely known for his extensive 
dealings in natural history specimens; the ‘‘Scientific 
Kstablishment’’ that he founded in Rochester was the 
source of many school and college collections: but unless 
by the rule of contraries it certainly cannot have been by 
the influence of this enthusiastic collector that Gilbert 
was led to say in the address, above quoted, that the 
important thing is to train scientists rather than to teach 
science, and that ‘‘the practical questions for the teacher 
are, whether it is possible by training to improve the 
guessing faculty, and if so, how is it to be done.’”’ It 
must have been Gilbert’s own idea, not his professor’s, 
that the content of a science is often presented so abun- 
dantly as to obstruct the communication of its essence, 
and that the teacher ‘‘will do better to contract the phe- 
nomenal and to enlarge the logical side of his subject, so 
as to dwell on the philosophy of the science rather than 
on its material.’’ 

The young graduate having no decided bent toward 
any profession or occupation, but having reached the 
pedagogically mature age of 19, taught school for a year 
at Jackson, Michigan, not as the beginning of a career, 
but, young-American like, as a means of paying off a debt 
which his college course had occasioned. Then returning 
to Rochester, he entered geology through being employed 
for five years as an assistant in Ward’s Scientific Estab- 
lishment above mentioned. His work there included 
the sorting and naming of countless specimens; many 
thousand labels in the Ward collection, afterwards 
acquired by the University of Rochester, are in Gilbert’s 


672 3 Grove Karl Gilbert. 


writing. He had also to do with the installation of ex- 
hibits in museums; it may have been in the course of 
journeys then undertaken that he learned something of 
the Appalachians, to which he refers in a most appre- ~ 
ciative manner in his first western report. 

The philosophy of geology could have been learned no 
better during these five laborious years of clerkship than 
during the preceding eight years of school and college 
study; yet a liking for the science seems to have grown 
up, for Gilbert next became a volunteer assistant on the 
Ohio Geological Survey, where he worked under New- 
berry from 1868 to 1870, receiving pay only for his field 
expenses. His drawings of fossil fishes are praised by 
his chief, but the best known result of this period of 
apprenticeship is his report on the surface geology of 
the Maumee ‘‘valley,’’ a district of very faint relief lying - 
southwest of Lake Erie. It is interesting now to note 
that Gilbert here attributed the higher levels of the lake, 
as attested by abandoned shorelines on the adjoining 
plains, to a former upwarping of the land in the lower 
St. Lawrence valley, an idea which he mentioned again 
five years later in his report on the Henry mountains; it 
was Newberry who, in a footnote, explained the higher 
lake levels by a retreating glacial barrier. When Gil- 
bert was fifteen years older and greatly matured by his 
studies in the West, he returned to the region of the Great 
Lakes and recognizing the correctness ef Newberry’s 
opinion eventually brought out a masterful essay on the 
history of Niagara Falls, as will be further told below. 

Gilbert’s larger career began on the Wheeler Survey, 
which took him to Utah, Nevada and Arizona between 
1871 and 1874. His first season of western work led him 
into problems that engaged his lifelong interest. Would 
that we had a narrative of his personal experiences and 
his mental progress in those new surroundings! The 
several chapters in his reports cover a large range of 
subjects :—stratigraphy, voleanic phenomena, plateaus 
and canyons, glacial and lacustrine records, and. the 
mountain ranges of the Great Basin. Powell’s and Dut- 
ton’s more extended descriptions of the plateau province 
have distracted attention from the large contributions 
that Gilbert made to its elucidation. On the other hand 
the Basin ranges and the Lake Bonneville came to be 
regarded as peculiarly Gilbert’s problems. 

The theoretical discussion of the Basin ranges, fon the . 


Grove Karl Gilbert. ! 673 


origin of which Gilbert proposed an altogether new inter- 
pretation, is regrettably brief; but it is fortunately 
recorded that the Great Basin was entered with the 
expectation of finding the hard rocks standing in relief, 
and the weak rocks worn down in valleys: and low- 
lands, as he knew them to be in the Appalachians; and 
on discovering that the Basin ranges ‘‘oecupy loci of 
upheaval and are not mere residua of denudation’’—to 
quote his classico-mathematical phrase—he was greatly 
surprised. ‘‘The valleys of the system jz. e. the broad 
intermont depressions] are not valleys of erosion but 
mere intervals between lines of maximum uplift. Within 
the ranges there are indeed eroded valleys, and the 
details of relief show the inequalities of erosion due to 
unequal resistance; but there is not on a grand scale that 
close dependence of form on durability that must main- 
tain where the great features of the country are carved 
by denuding agents.’’ The ridges were found to be more 
persistent than the structures; one was instanced across 
which an anticline runs obliquely. The excavation of 
the broad intermediate depressions by erosion, while the 
ranges remained in bold relief, was seen to be impossible. 
The valleys were, therefore, explained as belts of relative 
depression, and the ranges as belts of uphft. Thus began 
a long discussion which is not yet closed to the satis- 
faction of all concerned. The geologists of the Fortieth 
Parallel Survey had, before Gilbert had entered the field, 
interpreted the Basin ranges as prevailingly of anticlinal 
structure between broad and deep synclinal valleys; but 
Gilbert’s theory was afterward adopted to the extent of 
adding vertical displacements by faults to the earlier 
deformation by folding, yet without going so far as to 
give to the faults the dominant value in producing the 
existing relief that Gilbert had attributed to them. 
Unfortunately the leading chapter in Gilbert’s report 
concerning the Basin ranges occupied only twenty-two 
pages, and of these only a few at its end were devoted to 
theoretical discussion. This was by no means sufficient 
space for a clear exposition of his novel views; indeed it 
is not possible to ascertain from his text alone how fully 
he had worked out the ‘‘consequents’’ of the fault-block 
theory of mountain formation. The important physi- 
ographic principle that is involved in demonstrating the 
presence of a great fault by the truncation of diverse 
rock structures in simple alignment along the mountain 


Se 


674 Grove Karl Gilbert. 


base could not be easily apprehended from the few lines 
that Gilbert gave to it; indeed some of those geologists 
who, a quarter of a century later, opposed Gilbert’s view 
do not seem even then to have appreciated this essential 
element of his discussion. 

The regrettable brevity of the Basin-range chapter is 
perhaps to be explained by the dissatisfaction of its 
author with the military ordering of the Wheeler Survey. 
The young geologist had been permitted by Newberry to 
publish an abstract of his Maumee valley studies in the 
American Journal of Science two years before it came 
out in a volume of the Ohio Survey; but on asking a sim- 
ilar permission regarding some of his western work it 
was refused by General Humphreys, chief of engineers, 
under whose direction Lieutenant Wheeler’s Survey was 
conducted. Whether this was also the cause of Gilbert’s 
leaving the Wheeler and joining the Powell Survey does 
not appear; but on Nov. 27, 1874, after the transfer had 
been made, he wrote from his home in Rochester to 
Powell :—‘‘TI feel little ambition to write anything for 
publication with the uncertainty that would hang about 
the date of its appearance. . . . Iam getting a little 
anxious to be aty-work—partly because it has come to be 
more natural than play, and partly because I ought to be 
earning something. So I am going to Washington in a 
few days, with the intention—if you have not changed 
your mind—to begin work with you at once.’’ Thus he 
entered upon a period of the most loyal and substantial 
service under his new chief. 

In the course of his continued western field work, Gil- 
bert spent a week in the summer of 1875 in the Henry 
mountains of southern Utah, and found them so inter- 
esting that, probably on his own request, he was sent 
there for two months of 1876; as a result we have one 
of the most notable of all his reports. Its greater part 
treats the type of intrusive structures, previously recog- 
nized in a general way by earlier geological visitors, to 
which he gave the name of ‘‘laccolites.”’ This text 
clearly illustrated his power to deal convincingly, if he 
took the time, with a new structural problem, involving 
many local details. The report described an area of 
about 1000 square miles of desert, mountainous country, 
as surveyed on his two visits. Gilbert recognized that 
the time was short for so great a task, for he wrote :— 
‘¢\ few comprehensive views from mountain tops gave - 


Grove Karl Gilbert. 675 


the general distribution of the formations, and the 
remainder of the time was spent in the examination of 
the localities which best displayed the peculiar features 
of the structure. So thorough was the display and so 
satisfactory the examination, that in preparing my 
report I have felt less than ever before the desire to 
re-visit the field and prove my conclusions by more 
extended observations.’’ The method of presentation, 
beginning with covered laccoliths and ending with 
denuded and partly undermined laccoliths, is so persua- 
sive of the announced conclusions that the need of revis- 
ing them has seldom been suggested. 

The closing chapter of the Henry Mountains report, an 
essay on ‘‘Land Sculpture,’’ has in this country at least 
been of greater service though not of greater interest 
than the four which precede it. The contents of the 
famous essay cannot be analyzed here; but two pecu- 
liarities of its treatment may be mentioned. One is the 
lack of reference to similar work by foreign students, for 
though several Americans are named, Hopkins is the only 
European mentioned; and this was naturally enough 
unsatisfactory to geologists and geographers abroad; 
but the fact of the case seems to be that Gilbert, like most 
of his early colleagues, had never been trained in the 
time-consuming but dutiful labor of looking up the ‘‘lit- 
erature’’ of a subject, and that he was so absorbed in his 
western problems and so overwhelmed with the abund- 
ance of new material to be described, that he had no time 
to look across the ocean in search of precedents for his 
opinions. Another peculiarity, harder to account for, is 
the complete absence of Powell’s term, baselevel, which 
had been published in 1875; indeed even the fundamental 


_ principle embodied in the term is hardly touched upon, 


except in so far as it is tacitly implied in the discussion 
of ‘‘declivity.’’ 

The study of Lake Bonneville, which Gilbert began 
under Wheeler and continued under Powell, was carried 
farther in the field and published in more elaborate form 
than any other subject that he undertook. It became his 
own problem and is so still, although a new interpreta- 
tion of the shoreline chronology has been proposed by 
recent observers. The Bonneville monograph estab- 
lished a high standard with respect to which the records 
of vanished lakes in all arid continental basins must be 
treated. Its first sequel was Russell’s monograph on 


ete 
———— 


676 Grove Karl Gilbert. 


Lake Lahontan, but as yet it has had no other. The 
chapter on the ‘‘Topographic features of lake shores,’’ 
originally published as one of the brilliant essays with 
which Powell enriched his annual reports as director of 
the national Geological Survey, and reissued as the cor- 
nerstone of the final monograph, deserves special men- 
tion because it gave so great an impetus to rational 
physiography. It held good for sea shores as well as for 
lake shores, and every one of its uncounted readers must 
have discovered in it a fuller treatment of such shoreline 
features as he had somewhere seen than he had found in 
any text-book, and far better than he had prepared 
himself. 

The establishment of the United States Geological 
Survey in 1879 caused a fateful turn in Gilbert’s life. 
Its first effect was to give him unrivalled opportunity for 
the detailed study and—after delay owing to the intru- 
sion of other duties—the handsome publication of the 
Bonneville problem, as above noted; but its longer last- 
ing effect was to withdraw him from the western field, — 
where his work had been so fruitful and where he would 
have so gladly gone on working; he was not only placed 
for some years (1884-1888) in charge of Appalachian 
geology, but was for a time (1889-1892) burdened with 
the executive duties of ‘‘chief geologist,’’ a position for 
which he had neither especial fondness nor marked fit- 
ness. Yet when the director of the Survey called him to 
these duties, he put aside a cherished plan of continuing 
his work in the Great Basin—especially a research into 
the strength of the earth’s crust as indicated by the 
deformation of the Bonneville shorelines—and, with self- 
denying devotion, took up the tasks assigned to him: 
but he said, in his address on the ‘‘ Ineculeation of Scien- 
entific Method’’:—‘‘It is hardly necessary for me to 
assure you that my personal regret in abandoning this 
research at its present stage 1s very great.”’ 

Gilbert never reaped any significant public advantage 
from his supervision of the Appalachian division, for 
with characteristic generosity he gave such results as his 
limited opportunity for field work afforded to his 
assistants and his friends, as contributions to their more 
detailed investigations. As chief geologist he was in a 
manner embarrassed by his habit of deliberation, for 
Survey problems usually called for prompt decision. It 
was, therefore, fortunate that, when Powell withdrew . 


eed, 


Grove Karl Gilbert. 677 


from the Survey in 1894, it contained another man of 
conspicuous administrative capacity, well trained to 
carry on and to carry farther its great organization. 
The scientific world expected the new director to be Gil- 
bert, but he himself had no such ambition and was well 


content to return in his later years to scientific research. 


The ten years of Gilbert’s mature life that were largely 
spent in the West won for him a deservedly high place in 
geological science. The following twelve years spent 
largely in Washington gave him high rank among scien- 
tific men. The chief lesson of his western work comes 
rather from the transparent reasonableness of his meth- 
ods of investigation and—excepting the too-short chapter 
on the Basin ranges—from the delightful clearness of his 
style of presentation, than from the results that he 
reached, important as they were. The chief lesson of his 
life in Washington has not been fully recognized by his 
colleagues; it was a lesson not in science but in loyalty, 
the great lesson of self-sacrificing service. He gave up 
his own preference for investigation and turned largely 
to administrative duties, as they were seen by the chief 
under whom he had enlisted. Yet even thus, his effect 
on geological science, although for the most part anony- 
mous, was very great. His advice was highly valued in 
the Survey and outside of it. His opinien usually car- 
ried his associates far toward a conclusion. On termi- 
nology, correlation of formations, map coloring, form of 
folhos, and other technical matters he submitted serious, 
even elaborate discussions, some of which were published 
as a means of bringing Survey problems more clearly to 
the attention of American geologists. 

Happily his administrative duties inciuded close rela- 
tions with many younger men, and this was as enjoyable 
to Gilbert as it was profitable to his juniors, for his 
nature was kindly, patient and sympathetic. Those who 
had to report their work to him carried away inspiration 
from every contact. The encouragement of his approval 
was a spur to new effort. To one of his subordinates 
with whom he was reviewing the proposed solution of a 
problem in the field, he said rather brusquely after a 
reflective pause at the end of the day:—‘‘How did you 


find it out?’’ This brief remark was then taken and is 


still treasured as the highest reward of a long study; for 
if, after hearing the solution of a problem, that keen in- 
vestigator cared to ask how it had been found out. . .! 


678 Grove Karl Gilbert. 


Gilbert’s helpful influence extended far beyond the 
Survey office in Washington. When articles and reviews 
appealed to him, he had the pleasant way of writing a 
note of appreciation to their authors; and these spon- 
taneous expressions of approval from so competent a 
critic won for him the warm regard of many younger men 
who had little or no personal acquaintance with him. 
Indeed two generations of American geologists enter- 
tained toward this master of their science a sentiment 
that approached affection more closely than is common 
among men. It was about as much as an expression of 
personal regard as of scientific esteem that he was chosen 
president of nearly every learned society of which he 
was a member. His bearing in the chair had a simple 
dignity that was very acceptable to his constituencies. 
He was a welcome speaker at all scientific gatherings 
where his fine presence went well with his exceptional 
clearness of exposition. 

In personal relations he was frank and outspoken, free 
from all formalities, a delightful companion indoors and 
out, with a lively sense of humor and a merry laugh. 
Indeed he was often by no means so serious as he looked. 
On meeting an over-assiduous correspondent he said :— 
‘“T received a long circular letter from you lately, and I’ve 
put it away ina safe place.’’ His whispered comment on 
a speaker who had made an inconclusive reply in a dis- 
cussion was in the western phrase :—‘‘ You can’t prove it 
by him.’’? A friend once inquired whether a visiting 
Kuropean geographer of distinction, whom Gilbert had 
ouided on an excursion, was quick in responding to field 
evidence. ‘‘Hair trigger,’’ was the concise reply. Not 
long afterwards when the inquirer repeated the charac- 
terization to its beneficiary—alas for the break of rela- 
tions with him in these troubled years !—it brought forth 
the puzzled exclamation—‘‘ Vat is ‘hair trigger’?’’—but 
the phrase gave much satisfaction when explained. 

After Gilbert’s relief from the position of chief geol- 
ogist of the National Survey, he continued for a time in 
charge of correlation problems, and was then (1893-96) 
assigned to study certain areas of the great plains, where 
he prepared two geologic folios. In later years he held 
various roving commissions. Among these were the 
study of the Great Lakes region, which he had already 
taken up in 1885 as if for vacation exercise in thefield, 
and in which he had then at once made the fruitful dis- . 


Grove Karl Gilbert. 679 


covery that the ancient shorelines, which he had earlier 
known in the Maumee valley, southwest of Lake Erie, 
- ascended to the northeast. This compelled him to give 
up the idea he had originally entertained, that the lakes 
had been raised by an upheaval of the land in the 
St. Lawrence district, and to adopt Newberry’s view that 
the high-level lakes were enclosed by a retreating glacial 
barrier. Intermittent attention to this problem resulted 
in 1896 in a ‘‘History of the Niagara River,’’ a most 
luminous generalization, published in the Sixth Report of 
the Commissioners for the [N. Y.] State Reservation at 
Niagara. More formal study, when the Great Lakes 
came to be an official assignment (1896-97), produced 
a report on ‘‘Karth Movements in the Great Lakes 
Region,’’ published in the 18th Annual Report of the 
Director of the Survey. 

In 1899, Gilbert visited Alaska as a member of the 
Harriman expedition and there recognized the convine- 
ing evidence of intense glacial erosion that is given by 
the much greater depths of the main fiord troughs than of 
their lateral tributaries, for which it was he who sug- 
gested the name of ‘‘hanging valleys.’’ His observa- 
tions are reported in a fine volume on Alaskan Glaciers, 
where he brought forth the noteworthy idea that glaciers 
which invade the sea rest so heavily on their trough floor 
that no sea water can enter beneath to buoy them up; 
and that they therefore continue to press upon and to 
erode their floor with their whole weight, even if six- 
sevenths or more of their thickness is submerged. The 
San Francisco earthquake was later the subject of study, 
and following this came his last formal work, an exam- 
ination of the conditions under which gravels have been 
spread forth from hydraulic gold washings in California ; 
this resulted in Professional Paper No. 86 of the 
Survey, entitled ‘‘The Transportation of Débris by 
Streams.’’ During the progress of these two studies, 
Gilbert was frequently at Berkeley, where he was a wel- 
come ‘guest of the hospitable Faculty Club of the Uni- 
versity of California, as he was also of the enterprising 
‘‘Sierra Club’”’ of San Francisco during its summer 
excursions in the mountains. 

The breadth of Gilbert’s interests is shown by the many 
topics on which he wrote besides those already enumer- 
ated. They include, among others, barometric hypso- 
metry, the percentage of success and error in weather 


a _—- 


ann ~~ —— re 
—— — 


eee 


———— ee 


= =- = 


— 
{ 


680 Grove Karl Gilbert. 


prediction—but the misprints in this article in the 
American Meteorological Journal were so numerous that 
its author had no satisfaction in it—ripple marks, joints, 
the sufficiency of terrestrial rotation for the deflection of 
streams, the origin of the ‘‘craters’’ of the moon, which 
he suggested might be the result of meteoric impacts, an 
idea that he later applied also to Coon Butte in Arizona 
in an address on the ‘‘Origin of Hypotheses’’ (1896) ; the 
systematic asymmetry of mountain crests in the Sierra 
Nevada as a result of glacial erosion, and the convexity 
of hill tops as a result of soil creep—a small problem that 
he had left unsolved nearly forty years earlier in the 
chapter on Land Sculpture in the Henry Mountains 
report. He also collaborated in producing an elemen- 
tary text-book on Physical Geography. 

In all these studies, his keen insight tended, as has been 
well said, ‘‘to bring into declared form the basal prin- 
ciples that underlie the phenomena in hand.’’ He was 
thus led to understand earlier than many of. his col- 
leagues that the Adirondacks were not, as had long been 
thought and taught, a rising but a sinking land mass 
when the Potsdam sandstones were laid unconformably 
on their flanks; and that the fresh-water Tertiaries of the 
Rocky mountain region had not been deposited in great 
lake basins, a long prevalent view that he had himself 
adopted in his early western work, but that they were 
largely deposited by aggrading streams. It was, there- 
fore, in view of the breadth as well as the depth of his 
researches that he was awarded the Wollaston medal by 
the Geological Society of London in 1897, and the Walker 
Grand Prize—a thousand dollars—by the Boston Society 
of Natural History in 1908. 

It remains to recur briefly to Gilbert’s return to the 
Great Basin in 1901, with the object of revising the field 
of his early work on the origin of the Basin ranges; for 
a new discussion of the old problem had been awakened 
by a junior geologist who expressed strong dissent from 
the fault-block theory. A season of successful field work 
supplied the veteran observer with more detailed evi- 
dence than had been before available for the correctness 
of his theory—which, it mav be noted, had received inde- 
pendent confirmation from Russell’s werk in Nevada and 
Oregon some years before, and was about to gain still fur- 
ther support from studies bv Campbell in Death valley 
and by Louderback on the Humboldt ranges; but most. 


Grove Karl Gilbert. 681 


unhappily the maps on which much of Gilbert’s new 
_ observations had been recorded were destroyed by sad 
mischance in the following winter, and under this dis- 
couragement further field work was suspended. The 
main results of the study were, however, presented at a 
meeting of the Geological Society of America in Wash- 
ington in the winter of 1903-04, in a manner that was 
convincing to many if not to all hearers; but the printed 
record in the Society’s Bulletin was compressed into a 
few lines, which merely state that the evidence of great 
faulting lies in the occurrence of extensive shear zones, in 
triangular facets at ridge ends, and in the even linear 
bases of the ranges. Thus, in spite of the clear concep- 
tion of the problem indicated by Gilbert’s oral presenta- 
tion, the printed record remains deficient. 

The loss of the map was probably the larger cause of 
this brevity, but a contributing cause was failing health, 
as a result of which it had become increasingly difficult 
for this master of exposition to apply himself to writing. 
For the same reason he later had to forego attendance at 
scientific meetings and participation im discussions. 
Thus at the very time when all his associates would have 
most delighted to welcome and to honor him, they saw the 
least of him; yet those who were still favored to meet 
him found, if not the same strength, the same noble 
geniality that they had learned before to love admiringly. 
Indeed, these years of withdrawal were marked by a 
serenity of mind that made his face more than ever 
benign. All his fine qualities seemed to shine forth 
undimmed:—openness of mind, breadth of sympathy, 
calmness of judgment, mental honesty, sincere humility 
in the contemplation of mysteries unsolved. One of Gil- 
bert’s last projects, after the completion of his two Cali- 
fornia tasks, was to visit for the third time the scene of 
his early work and to take up yet again the origin of the 
Basin ranges, but health failed him. In the spring of 
the present year many of his friends, acting on a sugges- 
tion from the office of the Survey where he had so faith- 
fully labored, wrote letters of congratulation that were 
to be presented to him on his seventy-fifth birthday; but 
these messages of affectionate regard failed to reach him 
by the narrow interval of five days. He died at Jackson, 
Michigan, on May 1. 
Wiuiam. M. Davis. 


682 Henry Shaler Williams. 


HENRY SHALER WILLIAMS. 
An APPRECIATION OF HIS WorRK IN STRATIGRAPHY. 


Henry SHALER WILLIAMS, professor of geology in Cor- 
nell University, was born at Ithaca, New York, on March 
6, 1847, and died at the age of seventy-one years, in 
Havana, Cuba, on July 31, 1918.2 

His first two publications relate to zoology, but all of 
the subsequent ones have to do with geology, paleontol- 
ogy, evolution, biography, and teaching. He was the 
author of upwards of ninety papers and books, compris- 
ing nearly three thousand pages, and of these about 
sixty-five titles relate to stratigraphy. Incidental to his 
studies, he has described sixteen new genera and more 
than one hundred and forty new species of fossils. He 
was also the originator of the Sigma Xi Society. 

Professor Williams was one of the two authorities on 
the American Devonian faunas and formations, though 
he also did work on the Silurian and Mississippian sys- 
tems. He seems to have been directed into geology, and 
more particularly into the study of the Devonian, by his 
environment at Ithaca, where he spent most of his life, 
and the geology of which he has made better known than 
that of any other part of New York State, the richest 
Devonian field in North America. A reading of his 
many publications, issued during nearly forty-five years, 
shows a progression from the detailed description of the 
faunal successions to an ever deeper philosophic pene- 
tration into the significance of stratigraphy and fossil 
faunas. He tells us again and again that it is only the 
fossil content of the formations that wili yield a true 
chronogenesis of the earth, but he also points out not 
only that the organisms varied and evolved with time, 
but also that the faunas are continually altering their 
specific combinations, and further that they shifted about 
with the migrating facies of the sea bottoms. ‘Therefore, 
the organic succession can not be learned from a single, 
or even for that matter from several sections; one must 
study a wide field to glean the actual history of 
organisms. These conclusions he began to see as early 
as 1884, and the further one that stratigraphers must 
abandon the then accepted canon that each geologic 


*A brief notice of his life is given in the September number, p. 550. 


Henry Shaler Williams. 683 


formation has its own distinct set of organisms. To 
Professor Williams, more than to any other American 
stratigrapher, de we owe our present marked insight into 
the fact that the marine faunas of the past have shifted 
about so much that only the expert of many years’ expe- 
rience can discern in them their true correlation values. 

The mind of Professor Williams was distinctly analy- 
tical, philosophical, and cautious—possibly over-cau- 
tious. He loved to pick out the parts of a problem and to 
define them. The components of a series of faunal 
assemblages were examined in the greatest detail, not 
only as to their minute changes in the acquisition or loss 
of characters, but as to their numerical presence as well. 
On the other hand, he must at times have been lost in the 
labyrinth of observed detail. All of these studies he 
thought necessary to find out, both how the assemblages 
change so that the same congeries indicate a given 
geologic time, and why these changes and shiftings 
occur. 

The leading line of study with Professor Williams was 
that of the Devonian of America east of the Mississippi 
River, and chiefly of the New York, Maine, and the Appa- 
lachian areas. Here he sought to learn what were the 
successive faunas in a given section and how the species 
and their assemblages differed among themselves over a 
wide geographic area. He therefore studied the stratig- 
raphy in detail, and collected the faunas bed by bed along 
ten or more parallel meridians near enough to one 
another, in the states of New York and Pennsylvania, to 
make it possible to compare the corresponding zones of 
the various formations studied. This is the Wilhams 
method of stratigraphic study, and one of which he 
appears to have been the inventor. In this way, he 
proved ‘‘that the composition of a fossil fauna changes in 
passing geographically from one place to another. Upon 
tracing single species across these sections, it was 
learned that the mutation of the species not only may be 
recognized on passing vertically upward through a con- 
tinuous section, but that the more direct line of succession 
was often deflected laterally so that the immediate suc- 
cessor of a particular fauna of one section was found not 
directly above it in the same section, but at a higher 
horizon in a section ten or twenty miles distant. This 
shifting of faunas was taken as actual evidence of migra- 


a 8 ___ ee 


ya — te — re i ne 
t 


684 Henry Shaler Williams. 


tion’’ (The Scope of Paleontology and its Value to Geol- 
ogists, 1892). | 

As the nature of the marine bottoms are shifted 
geographically, due to filling, scour or erustal move- 
ments, the faunas move with them, and if the environ- 
ments are not otherwise changed, the species will go on 
living without marked evolution. In this way the bulk 
of the faunas in a given region may continue to live a 
very long time by shifting with their special habitats, but 
locally the assemblages are found to be restricted to 
their facies in a given formation. On the other hand, 
migration is a very different organic movement, in that 
new forms or migrants appear among native faunas, 
having had their ancestral history elsewhere than in the 
area into which they migrate. We are told that ‘‘slight 
mutations of the species take place wherever the fauna 
as a whole shifts its place of habitation.’?’ Many new 
species ‘‘are undoubtedly mutants of the species of the 
previous dominant fauna’’ (Shifting of Faunas as a 
Problem of Stratigraphic Geology, 1903). 

Professor Williams began to see in 1884 that at the 
Cayuga Lake meridian the Devonian section ‘‘is Ham- 
ilton, terminating with Tully limestone and Genesee 
shale, then the Ithaca group, which has first a Portage 
fauna, then the Ithaca fauna, third, the Portage fauna 
again, and finally Chemung capped by Catskill and 
Carboniferous. A little further east in the Chenango 
valley, itis Hamilton; then a fauna intermediate between 
Hamilton and Ithaca (but no Tully or Genesee); then 
the Oneonta, a brackish and fresh water fauna; then the 
late Ithaca fauna, still with Hamilton types in it; no 
Portage fauna, but a Chemung fauna following the upper 
Ithaea fauna’’ (Dual Nomenclature in Geological Classi- 
fication, 1894). We therefore see that the actual sequence 
of faunas in a given section is not ‘‘necessarily expres- 
sive of biologic sequence’’ in the history of organisms 
(On the Classification of the Upper Devonian, 1886). 

The Catskill formation, long thought to be younger 
than the Chemung, Williams demonstrated to be contem- 
poraneous with it. Harly in his studies he said that the 
Catskill deposits are ‘‘due to the encroachment of the 
land and fresh water conditions upon the marine basin in 
which the Chemung fauna flourished. The Chemung 
faunas continued to live there so long as the marine con- 
ditions were sufficiently pure to maintain their life, and I 


Henry Shaler Williams. 689 


take it that there is nothing inconsistent in the view that 
Catskill rocks were being ‘deposited in the Appalachian 
region at the same time that Chemung rocks were being 
formed over western New York areas and during the 
reign of the Chemung faunas’’ (On the Fossil Faunas of 
the Upper Devonian. The Genesee Section, 1887). 

Recurrent faunules have been traced by Williams 
through a thickness of ‘‘about 2000 feet of sediments.’’ 
A ‘‘half-dozen fossils of particular species occurring 
together’’ can not determine the stratigraphic horizon; 
all they can do is to show that their time horizon is 
‘‘somewhere within one or two thousand feet of thick- 
ness of strata.’’ We are then forced to the conclusion 
‘‘that not only lthologic but paleontologic facts are 
local.’? He states that the fossils undoubtedly are the 
means on which we chiefly rely for determining that kind 
of equivalence which is called contemporaneity and 
homotaxy; but it must not be overlooked that species and 
genera of fossils may be extremely long ranging (Bear- 
ing of some new Paleontologic Facts on Nomenclature 
and Classification of Sedimentary Formations, 1905). 

_ At the southern end of Lake Canandaigua, J. M. Clarke 

discovered an Upper Devonian fauna, 550 feet above the 
Genesee formation, that has come to be known as the 
High Point fauna. On becoming aware of this fauna, 
Williams saw that it was closely related to the Rockford 
fauna of Iowa and widely different from that of the 
Upper Devonian of New York, ‘‘in the midst of which it 
lay.’? Further analysis of the fauna led to the discovery 
‘‘that the species peculiar to it apparently had their 
ancestors in the Middle Devonian of Kurope’’ and not in 
that of America. This study then led him into that of 
the Tully limestone of New York, where he found much 
of the Cuboides fauna of Europe and Asia. This fauna 
begins abruptly above the Hamilton, ‘‘and from it 
upward, all through the Upper Devonian, is a fauna 
closely related in its species with the Upper Devonian’’ 
of Kurope, Asia, British America, Iowa, and Nevada. 
We see here the pointing out of a world-wide faunal 
migration (Scope of Paleontology, 1892). 

Williams also pointed out that the Hamilton fauna has 
its closest affinities in the Lower Devonian faunas of 
South America, a fact first demonstrated by Steinmann 
and Ulrich. These migrations ceased with the Hamilton, 
at the close of which time there was crustal elevation 


Am. Jour. Sct.—FourtH Series, Vout. XLVI, No. 275.—NovemBER, 1918. 


ox 


686 Henry Shaler Williams. 


‘‘sufficient to occasion erosion in the southern area of the 
Mississippian sea’’ (Scope of Paleontology, 1892). 

As early as 1894 Williams began to point out the neces- 
sity of a dual nomenclature in geological classification. 


_ He then clearly showed that geologic formations have (1) 


a local and definite lithologic value in a sequence of strata, 
which in a wider distribution may become more and more 
indefinite lithologically; and (2) a variable time value in 
the general history of the earth and in the evclution of its 
organisms. Formations therefore have two values, and 
we should not confuse them in our geologic classification. 
In other words, there should be two sets of geologic 
terms, one expressive of sediments, and another of time. 

In his Correlation Papers of the Devonian and Carbon- 
iferous (1891), Professor Williams found it impossible 
to give ‘‘a thorough paleontologic definition of the sys- 
tems and series under consideration. The result has 
demonstrated that the facts are not yet accumulated to 
make this possible.’’ Later on we find that he helped to 
delimit the upper boundary of the Devonian, drawing the 
line suecessfully between the Chemung and Catskill 
formations on the one side, and the Waverlian on the 
other. 

In regard to the lower boundary of the Devonian, how- 
ever, he was not so successful. At first he accepted the 
prevalent view that the Oriskany forms the base of the 
Devonian. This view was challenged in 1889 by J. M. 
Clarke, who referred all of the Lower Helderberg to 
the Devonian, and thus closed the Silurian with the 
Waterlime or Bertie formation. This conclusion finally 
brought forth Williams’s paper The Silurian-Devonian 
Boundary in North America, The Chapman Sandstone 
Fauna (1900). Here he wrongly conciudes that ‘‘The 
Chapman fauna must be regarded as the equivalent of 
the topmost fauna of the typical Welsh Silurian system 
(—Upper Ludlow, Tilestone, Downton and Ledbury 
formations) ...:: . and of the uppermest simicare 
fauna of Nova Scotia.’’ ‘This places the Silurian- 
Devonian boundary for North America at the place 
where it was determined by De Verneuil in 1847.’’ On 
the other hand, he is near the truth when he states that 
the Chapman fauna ‘‘is equivalent to the Lower Oriskany 
fauna’’ of New York. Ina later paper, however, he cor- 
rectly says that the Chapman fauna ‘‘seems to be strictly 


Henry Shaler Williams. 687 


Lower Devonian’’ and that ‘‘it is a later fauna than the 
Tilestone or Downtonian of Great Britain or the terminal 
marine fauna of Arisaig, Nova Scotia’’ (1916). 

In regard to evolution, Professor Williams always 
fully accepted the fact. To him, species are as mutable 
as are organisms. ‘‘The principle of mutability must be 
recognized in the phenomena of development before we 
can rightly comprehend the laws of organic life.’’ 
‘‘Variability is the expression of the fundamental energy 
of the organism, and is not an irregular accident. 
- Heredity is the expression of the acquired adjustment of 
the organism to the conditions of its existence. Mutable 
heredity sounds like a contradiction; so did mutable 
species a century ago; but it is only as heredity is muta- 
ble that evolution is possible’’ (On the Genetic Energy 
of Organisms, 1898). 

‘We must seek for the immediate determined causes of 
variation not in natural selection, nor in any of the envi- 
ronmental conditions, either direct or indirect, by which 
hereditary repetition is established, but in the phenomena 
of individual growth and development, and in the more 
fundamental processes of cell growth and metabolism’’ 
(Variation versus Heredity, 1898). 

‘Whether the vital phenomena are latent in matter or 
not is a matter of speculation. Whenever vital phenom- 
ena appeared, they appeared in phenomena exhibited by 
matter. Whenever inorganic matter becomes vitalized, 
however that result may be accomplished, variation takes 
place and distinguishes it from matter in every other 
condition.’’ ‘‘Variation, as a process of becoming dif- 
ferent, is a characteristic of living bodies’’ (On, the 
Theory of Organic Variation, 1897). 

In retrospect we may say that Professor Williams 
worked long and faithfully, attaining good results, and 
that most of his work will be woven into the permanent 
record of Historical Geology. We see him far more 
effective and better understood in his writings than in 
his. public speaking and teaching. His publications are 
the record of work well done, and to the succeeding gen- 
erations of geologists they will be the living thoughts of 
Henry Shaler Williams. 


CHARLES SCHUCHERT. 


688 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. CueEmistry AND Purysics. 


1. A.New Method for the Quantitatiwe Estumation of Vapors 
in Gases—A process has been described for this purpose by 
Haroup 8. Davis and Mary Davinson Davis of the University of 
Manitoba. It is particularly interesting in its application of 
well-known principles in a new way. The apparatus consists of 
two flasks connected by a mercury manometer and provided with 
suitable outlets which can be closed, and a device for crushing 
small bulbs of quid within the flasks without changing their 
gaseous contents. When the flasks contain air or other gas under 
the same pressure, as shown by the manometer, for instance at 
atmospheric pressure, and then bulbs containing an excess of a 
volatile liquid are broken in each flask, this vapor, if it is the 
same in each case, will exert the same pressure by evaporation, 
and the manometer will remain unchanged. However, if a gas 
or air in one of the flasks is already partly (or wholly) saturated 
with the vapor of a liquid while the other flask is free from this 
vapor, then upon performing the same operation of saturation 
in both flasks, the manometer will show a difference of pressure 
due to the original partial saturation, and this serves as a means 
for determining the amount of vapor that was present. In this 
way the authors have succeeded in determining satisfactorily the 
amounts of benzene vapor in samples of air. For details of the 
apparatus and for other applications of the method the original 
articles must be referred to.—Jour. Indust. and Eng. Chem., 10, 
£09,712. 718. Fy tea ie 


2. The Determination of Organic Matter in Soils—The deter- 
mination of organic matter in soils by loss of weight upon the 
ignition of the substance gives highly erroneous results on account 
of the presence of hydrated minerals, carbonates, and unoxidized 
inorganic substances, while the determination of total and inor- 
ganic carbon in such materials gives uncertain results on account 
of the necessarily arbitrary factor that must be used in caleulat- 
ine the organic matter from the amount of organic earbon 
present. J.B. RatHer has now devised a method for this deter- 
mination which is based upon the treatment of the sample of 
soil successively with water and then repeatedly with a mixture 
of dilute hydrochloric and hydrofluoric acids. The residue is 
collected upon an asbestos filter, the solutions are evaporated 
to dryness, and a final ignition of the dried residues gives the 
amount of organic matter by loss. The details of the process 
will not be given here but it may be stated that the method 
appears to be the most satisfactory one yet devised for the pur- 
pose.—Jour. Indust. and Eng. Chem., 10, 439. H. L. W. 


Chemistry and Physics. 689 


3. A New Reaction for Osmium—M. L. TscHuGAEFF has 
found that when a solution containing osmium in the condition of 
tetroxide, OsO,, or of any chlorosmiate, for example, K,OsCl,, 
is heated for a few minutes with thiourea in excess and with a 
few drops of hydrochloric acid, the liquid becomes bright red or 
‘pink, according to the concentration of the osmium compound 
present. This reaction is very characteristic and permits the 
detection of osmium in a solution of 1 to 100,000. The red com- 
pound of osmium formed in this reaction, when crystallized, has 
a composition corresponding to the formula Os(N,H,CS),Cl,. 
H,O. Consequently it is a new base analogous to the luteo-salts 
of certain other metals, such as Cr(NH,),X,, Co(NH,),X, 
Rh(NH,),X,, and Ir(NH,),X,;.—Comptes Rendus, 167, 235. 

H. L. W. 

4. Chemical Combinations among Metals; by Dr. MicHELE 
Giua and Dr. Cuara Giua-Louuini. Translated by GILBERT 
Woopine Ropinson. 8vo, pp. 341. Philadelphia, 1918 (P. 
Blakiston’s Son & Co.).—This work gives an excellent account 
of metallic combinations from a chemical point of view. Many 
equilibrium diagrams based upon thermal analysis are given, 
showing the melting-points of alloys and the compounds, eutecties 
and solid solutions produced in them, and this subject is very 
fully explained. The microscopic side of the study of alloys is 
not treated in this book, but it furnishes an excellent introduction 
to the practical study of metallography. 

In its theoretical discussion of the subject the book emphasizes 
the importance of the phase rule of Willard Gibbs in connection 
with the study of alloys, and it may be noticed that several of 
the equilibrium diagrams are based upon the work of Professor 
Mathewson of Yale. H. L. W. 


a 


5. The Zinc Industry; by Ernest A. SmirH. 8vo, pp. 223. 
London, 1918 (Longmans, Green & Co.).—This is one of the 
extremely important and useful monographs on industrial chem- 
istry now being issued by the same publishers under the editor- 
ship of Sir Edward Thorpe. The work under consideration gives 
a general survey of the development and present condition of the 
zine industry. Many interesting statistics are presented, most of 
which do not apply to the period of the present war, but the effect © 
of the war upon the industry is extensively discussed, and the 
resulting great development of zine production in the United 
States-is mentioned. The sources of zine ores, zine smelting and 
other methods of production, the properties of the metal, its 
industrial applications, its alloys, etc., are discussed in a very 
satisfactory way. HL. W. 
6. Stoichiometry; by SypNEY Youne. 8vo, pp. 363. Lon- 
don, 1918 (Longmans, Green & Co.).—This is one of an extensive 
series of text books on physical chemistry, edited by the late Sir 
William Ramsay. The first edition of the book appeared in 1907, 


— .. ee 
ae 


690 Scientific Intelligence. 


and the present second edition has received a considerable amount 
of modification on account of recent advances in the science. The 
subject is treated in a broad sense, as the book deals with the 
fundamental laws of chemical combination, the general proper- 
ties of gases, the determination of atomic weights, the periodic 
law, the properties of liquids, the kinetic theory of-gases, the 


_ properties of solids, mixtures, solubility and miscibility, proper- 


ties of dilute solutions, dissolution and vaporization, and the 
determination of molecular weights. The topics are generally 
well presented from an advanced point of view, and the book 
appears to be an excellent and interesting one for the use of 
students of physical chemistry and teachers. Elda 


7. Hlements of General Science, Revised Edition; by Oris 
WILLIAM CALDWELL and WiuuIAM Lewis EIKENBERRY. Pp. xii, 
404; with 181 figures. Boston, 1918 (Ginn and Co.).—‘‘The 
course presented in this book is the result of ten years of experi- 
ment in secondary schools.’’. The main object of the course is to 
develop a usable fund of knowledge about common things and 
helpful and trustworthy habits of considering common experi- 
ences in the field of science. ‘‘The unity of this introductory 
course in science is secured by use of the logical interrelations 
between the topics which compose the course. No attempt is 
made to maintain the unity of any one of the different sciences. 
Experience shows that after use of this course pupils do not feel 
that they ‘‘have had’’ any of the differentiated sciences, as physi- 
ography, physics, chemistry, or biology. They are, however, 
much interested in the later study of the differentiated sciences. 
The topics of the course are readily grouped under six major 
divisions.’’ The titles of these six Parts are: The Air; Water 
and its Uses; The Earth in Relation to other Astronomical 
Bodies; The Earth’s Crust; and Life upon the Harth. The new 
edition has been almost entirely rewritten, and a laboratory man- 
ual has been prepared to serve as a guide in the performance of 
experiments and demonstrations. 

For lack of space it is not possible to enter into details con- 
cerning the discrete contents of the thirty-three chapters. Suf- 
fice it to say that the selection of material is excellent and that 
the manner of presentation leaves nothing to be desired. The 
diagrams and half-tone figures are clear cut and attractive, and 
the entire book is unusually interesting, instructive, and up to 
date. The volume deserves the careful attention of principals 
of high schools and other directors of education not only on 
account of its intrinsic merit but also because it contains a wealth 
of information concerning germ diseases, bacteria, flies, mosqui- 
toes, aleohol, hygiene, sanitation, reproduction in plants and ani- 
mals, ete., the thorough acquisition of which knowledge should 
have a most salutary influence upon the general welfare of 
society in the future. 18 Baye 108 


Miscellaneous Intelligence. 691 


8. Airplane Characteristics; by FREDERICK BrEpELL. Pp. iv, 
123. Ithaca, 1918 (Taylor & Co.).—In this book the principles 
of airplane sustentation and stability, and the characteristics of 
an airplane in flight, are presented in a manner that is simple, 
direct, and reasonably precise, special stress being laid on that 
which is vital. ‘‘The author has confined his attention to the 
principles of airplane flight and has given no discussion of 
materials of construction—very important, of course, in airplane 
building—nor of the gas engine, on which there are many special- 
ized treatises.’’ The sequence of subjects follows the logical 
order rather than the historical, and the use of higher mathe- 
matics so-called has been avoided. The present volume contains 
five chapters the titles of which are: Sustentation, Relations in 
Flight, Resistance, Lateral Stability, and Directional Stability. 
A supplementary volume, now in preparation, will contain such 
material as would logically follow immediately after the chapter 
on resistance. Accordingly it will deal with: Thrust, Power, 
Climbing, Gliding, Altitude, Single and Multiple Planes, Stabil- 
ity in General, and Longitudinal Stability. In addition to the 
five chapters mentioned above, the printed volume contains four 
appendixes, the first of which is a timely glossary, and the 
remaining three comprise a fairly large number of diagrams 
pertaining to thrust characteristics, power characteristics, con- 
trol, ete. 

The author’s style is, in general, lucid and concise, the material 
selected is very interesting as well as important, and the text- 
figures are numerous, clear-cut, and instructive. On the other 
hand, the book seems to show some signs of hasty preparation. 
Although susceptible of obvious correction, the typographical 
errors occur with sufficient frequency to annoy a reader who is 
sensitive to such causes of distraction. The term ‘‘angle of 
incidence,’’ although thoroughly established in physical and 
other scientific literature, is here defined as the complement of 
the accepted angle, hence it is the true ‘‘glancing angle,’’ now 
so familiar in the subject of X-rays. Again, the employment of 
such popular terms as ‘‘negative pressure’’ and ‘‘suction”’ 
detracts from scientific accuracy more than it enhances the clear- 
ness of exposition. Nevertheless, in spite of these little short- 
comings, the book is a valuable and much needed contribution 
to a very live subject. fel Sige 


— 


Il. Misceritanrous Screnvriric INTELLIGENCE. 


1. Medical Contributions to the Study of Evolution; by J. 
G. Apami. Pp. xviii, 372. New York, 1918 (The Macmillan 
Co.).—In this volume the author has brought together in orderly 
sequence and with some revision many of his earlier essays 
dealing with problems of evolution, and has grouped them under 


692 Scientific Intellugence. 


the general heading of Adaptation and Disease, Heredity and 
Adaptation, Growth and Overgrowth. Adami’s freedom of 
thought is made clear by this quotation: ‘‘ With abundant 
material presented to him and freedom of individual judgment, 
it is searce possible that the student of today should accept unre- 
servedly the teaching of either Lamarck or Darwin. He who is 
concerned at arriving at the truth is impatient of such labels.’ 
The viewpoint is summarized thus: ‘‘In so far as between Dar- 
win and Lamarck the essence of the teaching of the latter is that 
variation is an active process, a reaction on the part of living 
matter to its environment, the conclusions reached in these pages 
undoubtedly favour the Lamarckian view. Nevertheless, to 
accept them does not mean that the principle of natural selection 
is thereby excluded, or that the two principles are mutually 
antagonistic, but only that the influence of external forces is the 
primary process in the production of variation, and that natural 
selection is secondary, culling out those grades and forms of 
variation which are least economical and represent the less per- 
fect adaptation on the part of the individuals to the conditions 
in which the family or species finds itself for the time being. 
Seen thus, evolution, whether what we regard as progressive or 
as regressive, is the outcome of an active process of continuous 
adjustment between organisms and their environment.’’ The 
chapters are singularly replete with details applicable to scien- 
tific generalizations of this sort; and there is no lack of frank 
eriticisms of current views. It is a book disclosing many rather 
liberally conceived hypotheses, always presented in the guise of 
attractive diction. L. B. M. 


OBITUARY. 


Doctor CHARLES RocHESTER EKASTMAN, the well-known paleon- 
tologist, was drowned at Long Beach, New Jersey, during the 
night of September 27, 1918. He was born at Cedar Rapids, 
Iowa, June 5, 1868. A graduate of Harvard and of Munich, 
he was widely known and highly appreciated for his studies of 
fossil fishes, and as the editor of the English edition of Zittel’s 
Grundztige der Palaeontologie. His passing is a great loss to 
American science. Most of his work was done at Harvard, Car- 
negie Museum, U. S. National Museum, and the American 
Museum of Natural History. 

Doctor WinuiAM Barrie Puinuies, the mining engineer and 
geologist, died at his home, Houston, Texas, on June 7, 1918, at 
the age of sixty years. He has been connected with the univer- 
sities of North Carolina, Alabama, and Texas, and with the 
periodicals, the Engineering and Mining Journal and the Amer- 
ican Manufacturer and Iron World. He also organized the 
Bureau of Economic Geology and Technology in the University 
of Texas, and was ‘‘a man of great energy and of extensive 
learning.’’ ‘ 


iiecas 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


toe 


Arr, XXXVI.—The Origin of Serpentine, a Historical 
and Comparative Study; by W. N. Benson. 


I. Introduction. ’ 
II. The recognition of the intrusive character of serpentine-masses. 
Ill. The process of serpentinization. 
IV. The source of the water for serpentinization. 
V. The formation of nephrite. 
VI. The occurrence of serpentine in volcanic rocks. 
VII. Summary and conclusions. 


I. Introduction. 


Some years ago, the writer commenced work upon the 
Great Serpentine Belt of New South Wales, and was 
soon fascinated by the problem of the erigin of the ser- 
pentine. A study of the modern literature showed a 
general agreement that such serpentine-masses were 
originally peridotites, and have been hydrated by deep- 
seated process, in contrast with earlier text-books which 
explicitly referred the alteration to atmospheric weath- 
ering. It was noted that few publications compared and 
discussed the observations upon which the new view was 
based, but that instead there was a definite invitation to 
take up this study. ‘‘One might urge,’’ wrote Merrill 
(1899), ‘‘the necessity of closer observation regarding the 
formation of serpentine from olivine or other anhydrous 
magnesian silicates. That it is through a process of 
hydration is self-evident, but as to the conditions under 
which it goes on, literature is strangely silent.’’ ‘‘And,’’ 
added Bonney, ‘‘the subject would well repay any voung 
geologist with sufficient leisure’’ (1899). Since it was 


Am. Jour. Scr.—Fourts Series, VoL. XLVI, No. 276.—DrcemMBER, 1918. 


694 W. N. Benson—Origwm of Serpentine. 


necessary to investigate this matter for the fuller under- 
standing of the field-work undertaken, there seemed here 
an opportunity to accept the invitation to enter this field 
of research. In this the writer had the great privilege of 
working in Cambridge under the guidance and with the 
generous help of Professor Bonney. He has also been 
able to study material from Great Britain, the Pyrenees, 
Switzerland, Germany, Austria, Australia, and New Zea- 
land in the collections of Bonney, Becke, Lacroix, Preis- 
werk, Rosenbusch and Weinschenk, of the Geological 
Survey of Great Britain and of several Continental and 
Australian universities. The paper discusses chiefly the 
origin and alteration of the serpentines derived from plu- 
tonic masses; it does not deal in detail with the physical 
characters of the different serpentine minerals, which have 
been recently exhaustively reviewed by Bonney (1905, 
1908),1 and Lacroix (1903), or of the chemical features, 
which have been treated by Leitmeier (1913). For a 
complete treatment of the whole subject it would have 
been necessary to review fully the origin of nephrite in 
serpentine-masses, and of the alterations undergone by 
olivine in volcanic rocks, but to these points the writer’s 
studies have been less directed, and they are, therefore, 
but briefly considered. 


IT. The Recognition of the Intrusive Character of Serpentine- 
Masses. 


The origin of serpentine has been discussed since the 
beginning of the scientific study of geology. The earliest 
work has been summarized at various times by Weigand 
(1875), Hunt (1883), Teall (1883), Weinschenk (1891), 
and Zirkel (1894), so that we may devote our attention to 
the last two decades. The close association of the ser- 
pentines with the crystalline schists, and often with the 
crystalline limestones on the one hand, and with the mas- 
sive igneous rocks on the other, long proved a source 
of perplexity. So also did the extreme rarity of dikes of 
serpentine crossing the structural planes of the rocks in 
which they occur. Patrin, De Saussure, Humbolt, Bay- 
reuth, and Jameson considered the serpentine to be 
regularly interbedded with the stratified series, while 


+The dates given with the names of authors refer to articles noted in 
the bibliography at the end of this paper; in this list the full titles have 
of necessity been omitted in most cases. 


W. N. Benson—Origin of Serpentine. 695 


Von Buch, De la Beche, Brongniart, De Beaumont and 
others claimed it was of igneous origin, being followed in 
this by Whitney and Rogers in America. Some authors, 
like Macculloch, considered it possible that serpentine 
might originate both from igneous or sedimentary 
processes (for literature see Hunt, 1883). De la Beche 
was particularly clear in his recognition of the intrusive 
origin of the serpentines, and stated with regard to those 
of Liguria, that they were ‘‘thrust into the Oolitic rocks, 
but not into the supra-Cretaceous. ‘The intrusion is con- 
nected with earth-movements’’ (De la Beche 1831). 
He also claimed an igneous origin for the British serpen- 
tines. Haidinger (1823) held that the famous Snarum 
serpentine crystals were primary, but Breithaupt (1831) 
suggested that they were pseudomorphs after olivine, 
and intimated that augite and hornblende might be sim- 
larly changed. After twenty years cf discussion this 
conclusion was accepted as the result of Rose’s work 
(1851). 

Meanwhile the views of Rose and Bischoff (1854), as to 
the possibility of the metasomatic replacement of rocks 
by material introduced by percolating solutions, led to 
wide speculation. Almost any rock, it was assumed, 
could be transmuted into serpentine; the apparently 
eradual passage of a differentiated massif from granite 
into serpentinized peridotite was considered evidence of 
such a replacement. The necessary check to hypotheses 
of this character was given by the work of Sandberger 
1865-71) and. Tschermak (1867), the way for which 
had been suddenly opened by the discovery of the 
lherzolites of the Pyrenees by Des Cloiseaux (1862) and 
Damour: (1862), of the dunite of New Zealand by Hoch- 
stetter (1864), of the Scandinavian olivine-rocks by Kjer- 
ulf (1864), and of various Alpine peridotites. Sandber- 
ger showed that varying amounts of residual olivine and 
bronzite occurred in the serpentines of Saxony; 'T'scher- 
mak, the first to employ microscopical methods of inves- 
tigation, corroborated this, tracing the alteration of the 
olivine into serpentine, and describing the typical mesh- 
structure produced. He showed that the apparent 
passage of serpentine into aluminous gabbros and 
eclogites was due to an original heterogeneity of the rock- 
mass; the gabbros and eclogites do not become serpen- 
tine, but only the peridotites with which they are 
intimately associated. 


696 W. N. Benson—Origin of Serpentine. 


The discussion now passed to the question whether 
serpentines could be produced from any other rock than 
peridotite. Roth (1869) held that all non-aluminous 
ferromagnesian minerals could pass into serpentine, and 
that the process of change was the result of atmospheric 
weathering. Weigand (1875) claimed that the serpen- 
tines of the Rauenthal in the Vosges were derived from 
non-aluminous hornblende, and described the lattice- 
structure as evidence of this change. Professor Bonney 
(1887) expressed his doubts concerning this conclusion, 
and it was shown by Miss Raisin (1897) to be in part 
erroneous. Hussak (1882) described the knitted-struc- 
ture of antigorite-serpentine as indicating its origin from 
augite, studying the rocks from Windisch Matrei in the 
Austrian Tyrol, formerly termed ‘‘serpentine-like rocks’’ 
by Drasche (1871). Becke (1894) and Weinschenk 
(1894), who studied the same occurrence, have shown 
that antigorite could be derived from purely olivinie 
rock, and that the lattice and knitted-structures of ser- 
pentine could not be applied indiscriminately to deter- 
mine the origin of serpentinized rocks. The general 
unreliability of these structures in this connection has 
been further emphasized by Bonney (1905, 1908). That 
pyroxenes, both rhombie and monoclinic, and also amphi- 
bole, may be changed into serpentine is, however, recog- 
nized by him. 

Bonney had shown in 1877 the intrusive character of 
the serpentine of the Lizard, confirming De la Beche’s 
view (1839); later he proved the Ayrshire serpentines 
to be intrusive (Bonney 1878), though they had been held 
to typify the interbedding of serpentine with slates, and 
in the following year he confirmed the conclusions of 
Dela Beche (1831) and Jervis (1860) concerning the intru- 
sive character of the Ligurian serpentines (Bonney 
1879). Nevertheless, the apparent interbedding of these 
rocks with the sediments caused them to be considered 
in some way different from normal igneous rocks. Tara- 
melli (1884) and Dieulafait (1881) held that they were 
chemical precipitates formed by the passage of hot 
springs of alkaline silicates into a sea enriched in mag- 
nesian salts; Stopanni (1880), Stefani (1876) and Issel 
(1879) considered that they were submarine lavas, which 
had been poured out over the Eocene sediments. This 
view was supported by Pantanelli (1880), who deseribed 


W. N. Benson—Origin of Serpentine. 697 


in detail the association with the serpentine of radio- 
larian rocks, first noted by Bonney (1879). Mazzuoli 
and Issel (1881), also Lotti (1883), following the sugges- 
tion of Daubrée (1879), held that. the lava had been 
erupted in a very hydrous condition. The associated 
gabbros were not considered igneous, but altered sedi- 
ments and volcanic muds. 

Stapff (1880) noted in the case of the serpentine of 
the St. Gotthardt, that its boundaries sometimes follow 
the stratification of the neighboring rock, but sometimes 
go across them, but added that there is no proof of the 
penetration of the serpentine-mass into the rocks encas- 
ing it. ‘‘Although we would not consider the serpentine 
to be an intrusive rock, we must remark that it could not 
have had precisely the same sedimentary origin as that 
supposed for the micaceous gneiss which encloses it. 
We may regard it as originally a deposit of hydrated 
silicate of magnesia formed by springs, and enclosed 
between the sediments which gave rise to the mica- 
schists.’’ The hydrated magnesian silicate is supposed 
to have been subsequently converted into anhydrous 
olivine, ete., which by a later hydration has generated 
serpentine. The apparently intrusive features are 
explained as the result of earth-folding acting upon 
structures with different powers of resistance. (Cited 
from Hunt, 1883.) 

A fact often mentioned in this discussion was the fre- 
quency of the association of serpentine and limestone 
in such a manner as to suggest genetic relationship, that 
e. g. the serpentine had been produced by the action of 
silicifying solutions upon magnesian limestones, with the 
production of olivine and peridotite, which subsequently 
became hydrated. There is no doubt that such a process 
has often occurred, notably in the case of some ophical- 
cites, and the Kozoon rocks, but the serpentine produced is 
not of the normal character; it is less dense, has a pale 
honey-yellow color, is poor in iron and free from chromite 
and nickel. These distinctions were recognized by Hunt 
(1883), who, however, believed that all serpentines were 
originally precipitates formed in pre-Cambrian times on 
the floor of a primordial ocean, and that masses of appar- 
ently intrusive serpentine, e. g. those among the Creta- 
ceous and Kocene rocks of Florence, were to be considered 
as inliers. The Italians recognized several ages for the 


698 W. N. Benson—Origmn of Serpentine. 


development of serpentine, Upper Hocene, Upper Trias, 
and Paleozoic or pre-Paleozoic, and a general discussion 
was held on the problem, at the meeting of the Interna- 
tional Geological Congress in Bologna in 1881. The pro- 
ceedings are recorded by Hunt, who presided (1883, pars. 
40-73), and in the first volume of the bulletins of the 
Italian Geological Society. Novarese’s work (1895) 
marks the acceptance by the Italian Geological Survey of 
the modern ideas concerning the nature of serpentine and 
the associated basic rocks, which had thus been foreshad- 
owed by English workers. 

It was about this time that the Spanish serpentines 
were first recognized as being derived from peridotites 
(Macpherson 1875). 

While this discussion was in progress in Europe, there 
were similar differences of opinion in America. The 
derivation of serpentine was referred to the alteration of 
olivine-sands (Raymond and King 1878, Julien 1882, Les- 
ley 1883), of volcanic agglomerate or diabase (Selwyn 
1883), of hydromica-schist (Fraser 1883) or the metaso- 
matic replacement of sandstone (Becker 1888), though 
in each of the localities described, the intrusive character 
of the serpentine has since been ascertained, by Lawson, 
Fairbanks, Lindgren, Ransome, Turner, Branner, Bas- 
com, Pratt, Lewis or others. Some authors (e. g 
Emmons 1855) like Macculloch held that serpentine could 
be either interstratified or intrusive, but Whitney (1851) 
and Rogers (1858) recognized them as intrusive, and 
were followed by others who declared the serpentines to 
be altered intrusive peridotites. Among these were Kerr, 
Smith, Genth (1875), Low (1883), Wadsworth (1884), 
Williams, Diller (1886), and Chester (1887), whose views 
were the orthodox teaching of their day, and have heen 
generally accepted ever since. The American literature 
has been summarized by Pratt and Lewis (1905) and a 
full bibliography will be found in their valuable work. 

The commencement of the last decade of the nineteenth 
century saw firmly established the recognition of the 
derivation of serpentine from intrusive peridotite, and 
we may add that this perplexing rarity of dikes formed 
of serpentine or peridotite, and the apparent interbed- 
ding of these rocks with those among which they occur, 
is an instance of those peculiar features attending the 
intrusion of ultrabasic rocks, that have been summarized 


W. N. Benson—Origin of Serpentine. 699 


in Suess’s statement that the ‘‘green rocks form sills in 
dislocated mountains, which sometimes follow the plane 
of bedding, and sometimes the plane of movement”’ 
(Suess, 1909). The association of normal serpentine 
with limestones is accidental except in so far as these 
comparatively weak structures may have determined the 
plane of intrusion (Trabucco 18967). 


III. The Process of Serpentimzation. 


The nature of the original rock from which the ser- 
pentine was derived having been thus ascertained, the 
discussion turned to those problems with which this 
paper is specially concerned, namely, actual process of 
serpentinization, the method, time and place in which the 
hydration occurred. Most writers prior to 1899, such as 
Teall (1888), McMahon (1890), and Roth (1869, 1893), 
but with the exception of Daubrée (1879), had referred 
the process to the action of percolating meteoric waters, 
z. e. to atmospheric weathering. In recent times Crosby 
(1914) also held this, and Julien (1914) has put forward 
in some detail his view concerning the development of 
serpentine by superficial action followed by a more 
deeply seated change. This interesting discussion may 
here be summarized. Julien divided into three stages 
the processes leading to the formation of antigorite, by 
which term he implied the mineral species, the composi- 
tion of which is expressed by the formula H,Mg,8i,0,, 
as distinct from the serpentine-rock, which is a mix- 
ture. (Whether this usage of the term ‘‘antigorite’’ 
is permissible is another matter.) The three stages 
are :—‘‘decay, the result of operations within the belt 
of weathering, disintegration and extreme hydration. 
Among the more important products are colloid magne- 
sian silicates of the first type (colloid deweylite, sepio- 
lite), magnesium oxide, hydrate and giobertite, besides 
various forms of ferrous and ferric hydrate, hydro-car- 
bonates, etc.; alteration to express the interchange and 
conséquent new formations, with great loss of water, 
which take their birth in a more deeply seated region, 
the common products of which are the magnesian hydro- 
silicates of the second type (tale, antigorite), hardened 
deweylite, forms of imonite, turgite, hematite, ete.; and 
decomposition to express molecular dissociation, still 
more complete interchanges, and still greater, to com- 


700 W. N. Benson—Origin of Serpentine. 


plete, dehydration, which have ensued within the zone 
of anamorphism. Examples of these products are peri- 
clase, spathic magnesite, dolomite, siderite, breunnerite, 
regenerated olivine, specular iron, magnetite, ete.’’? ‘‘In 
regard to the term ‘Hydrometamorphism,’ whether in 
the sense of Lindgren, referring to the action of meteoric 
or vadose waters, or that of G. P. Merrill, to the action 
of waters from deep-seated sources or from magmas, I 
find no application for it below the belt of weathering. 
There only has the highest hydration, below it every 
change has been attended with a progressive loss of 
water.’’ ‘‘EKiven the remarkable rocks of the Stubach- 
thal (discussed below) are explained in this manner.’’ 
‘‘Antigorite and tale, crystalline and never colloid, have 
merely served as insoluble fixatives to harden and record 
the transformations of their mobile and protean prede- — 
cessors. Chrysotile is but a pseudo-fibrous variety of 
antigorite, in fact a pseudomorph in antigorite, after a 
pseudomorph in deweylite, after nemalite, the fibrous 
form of brucite.’’ 

While the writer must record his dissent from some of 
these conclusions, it should be noted that Dr. Julien 
closed his paper by stating: ‘‘The evidence in confirma- 
tion of these views, from field. observations, optical exam- 
inations, ete., together with a review of the literature of 
brucite, serpentine, antigorite and the hydrous magne- 
sian minerals, have been gathered for presentation in a 
separate monograph.’’ By Dr. Julien’s lamented death 
in the Titanic disaster, this record of extensive and 
valuable observation has been lost to science. 

In 1891, Weinschenk stated that in the case of the ser- 
pentine of the Stubachthal, primary antigorite occurred 
intergrown with olivine, and had been formed from a 
hydrous magma crystallizing under high pressure, and 
that further the water emitted from the magma on con- 
solidation converted the remaining olivine into secondary 
antigorite. The distinction made between these is that 
the primary antigorite (which is admitted to be very 
rare) occurs in large well-formed plates regularly inter- 
erown with the olivine, generally parallel to the dome- 
face, while the secondary antigorite forms more or less 
irregular fine scaly aggregates. Moreover, there occur 
sharply defined veins of coarsely granular olivine and 
antigorite, which were injected after the serpentinization 


W. N. Benson—Origin of Serpentine. 701 


of the main mass of the rock, so that this process cannot 
be the result of atmospheric weathering, but of magmatic 
solutions (Weinschenk 1891, 1894). This important 
work will be further discussed below. By this hypothe- 
sis of crystallization under high pressure, a definite form 
was given to the.vague conception of a hydrous magma, 
previously suggested by Daubrée and the Italian work- 
ers. Becke, who studied an adjacent mass of antigor- 
ite-serpentine at the same time, also recognized that 
pressure was essential to its formation (Becke 1894). 
Somewhat similar phenomena have been described by 
Palache (1907), who found a narrow vein of olivine, two 
inches in width, traversing a serpentinized mass of peri- 
dotite made up of ‘‘platy serpentine’’ (antigorite?), and 
chiefly replacing olivine but also pyroxene. The olivine 
of the vein is vitreous in appearance, is in large crystals 
associated with chrysotile and sometimes brucite, and is 
sharply bounded from the massive rock. 

Support was given to the hypothesis of the origin of 
antigorite under pressure by Bonney (1905, 1908), but 
though thus demanding the deep-seated origin of antigor- 
ite, he does not conclude that it must result from the 
action of magmatic waters. Lindgren (1895) also advo- 
cated the deep-seated origin of serpentine, and the 
absence of any atmospheric action, pointing out that no 
change in the character of the serpentine is to be seen at 
whatever depth it is encountered in mining’ operations. 
Mennell has recently given evidence from South Africa 
corroborating this (1913). The most striking evidence 
of this known to the writer has not apparently been cited 
in discussions on this subject. Five kilometers inward 
from the north portal of the St. Gotthardt tunnel, and at 
a depth of 950 meters from the surface, is a mass of ultra- 
basic rock, 450 meters in width. On either side there is 
a marginal band of taleose carbonate (magnesite) rock, 
and within this there is on either side of the mass and 
again near its center, a zone of completely serpentinized 
rock,- while between the serpentine zones there is par- 
tially hydrated peridotite with 5-:3% H,O. This repetition 
of the central peridotite is believed to be due to fault- 
ing. The facts are displayed on fig. 1 (Stapff, 1878, 
1880, Bodmer-Beder 1903.) Almost directly above this 
serpentine in the tunnel, there occurs on the surface a 
mass of peridotite, surrounded by serpentine and car- 


702 W. N. Benson—Origin of Serpentine. 


Kies. 


Gneiss 
Amphibolite 


perpentine 


Lenticular Pericotity 


Massive Peridotite ; 


Schistose Peridotite [2 


Massive Peridotite 
Nephrife 


Serpentine 
Nephrite 


Lenticular Peridokike 


Massive Peridotite 
Analysis S:D3°% HO 


Nephrite 


2 B14 aad dosr\ng 
siyy Jo doy or8ojoary 104 


Serpentine = 
— 950 Metres — g 2 > 
co) 


Tale Carbonate Reck if 
Amphibolite 


Gneiss 


SS19Ub) 


Fic. 1. Part of geological section along the axis of the St. Gotthardt 
Tunnel (after Stapff, 1878) with detailed enlargement of part of same 
after Schneider (1912), based upon Stapff’s observations. 


Re) 


c (en 
Ho 
D (61% - 
. ey 
5- a 
ee 
F 8.92. Ss 
} "io Suc = ap ase 2 
ae Sea od SRE Ze ez — 
(60%) =e 2ST Sea a BPS Se 100 Yards 
bp rn ret - ae _ = 
tise Sie Ga EE og xe 
= 4s 1 i ETAT 
RAN Z 22-55 Earomota yyy 
Massive Lenticular Schistose Tale -Carbon- 
Gneiss Peridotite Peridatite Peridotite Serpentine - ote Rock Nebhrite 


Fic. 2. Map of the serpentines, etc., of Gigestafel near Andermatt. 
(After Schneider, 1912.) For complete analyses, see original paper. 


W. N. Benson—Origin of Serpentine. 708 


bonate rocks, which Stapff considers the extension of 
that encountered in the tunnel. It has recently been 
studied by Schneider (1912). So far as could be learned 
from the descriptions given and from a personal exam- 
ination of some of the material in the Museum of the 
University of Zurich, the rocks that appear on the sur- 
face are exactly similar to those occurring in the tunnel 
three thousand feet below. The water-content (loss on 
ignition) of samples from the center of the surface expo- 
sure varies from 5:8% to 8-5%, 2. e. is the same as that at 
depth, so that the evidence is clear that hydration does 
not depend on proximity to the surface. (See fig. 2.) 
The truth of this is shown again in the case of the 
dunite of the Geisspfad Pass studied by Preiswerk 


NAYS 
SQ Ny 


x MP. : 
2 Semen ara? 2 pa BES Feridotive and Serpentine 
Sad PPS aS Ce. Calc schist and Dolomite Mesozoic 
Pease ais = Two-mica GneiSs 


Fig. 3. Occurrence of the Geisspfad serpentine near the Simplon Tun- 
nel. (After Schmidt and Preiswerk, 1908.) 


(1901), (probably the source of the material from 
which Schweizer (1840) obtained the original antigorite 
described by him). In this the center is almost anhy- 
drous, but is surrounded by a zone of antigorite-bearing 
peridotite, the relation of the antigorite to the olivine 
recalling that of plagioclase to ophitic augite, while 
around this there is a marginal zone of completely 
hydrated schistose serpentine. The mass of ultrabasic 
rock.forms an almost horizontal sill in gneiss, and the 
upper hydrated layer is quite similar to the lower one 
from which it is separated by the anhydrous rock. (See 
fig. 3.) 

Effects that can be definitely referred to atmospheric 
weathering are very limited in depth. They consist of 
the formation of a crust sometimes attaining a depth of 


704 W. N. Benson—Origin of Serpentine. 


twelve feet, but more usually only a few inches in thick- 
ness, made up of limonite, with quartz, chaleedony and 
carbonates of iron and magnesia, together with a little 
chlorite or vermiculite, tale, and kaolin. Not infre- 
quently the carbonates are entirely absent. ‘This cover- 
ing forms from either peridotite or serpentine, and in the 


BGs 4 


sotescsee 
AL 


rs 
ea 


Cl Es 0 Fea 
ape 


= 


y 


Easse 


I 
ee 


1 


[J Dunite iacomre Galobyos 
peso Diorites 
Granites 


Schistose 
Basic Rocks 


awe Crystalline — 
Tilaites OM] seni s'"* 


Fic. 4. The Dunite mass of Taguil surrounded by pyroxenite and 
gabbro, showing the distribution of the serpentine. (After Wyssotsky, 
simplified; Mem. Comm. Geol. Russie, No. 62, 1913.) 


former case there is no evidence that serpentinization in 
its formation is a necessary antecedent or accompaniment. 
(See e. g. Pratt and Lewis 1905, pp. 112-119.) Even in 
the well-watered districts of southern India or of the 
southern end of the Appalachian Mountains, these 
changes do not proceed far from the surface, but on the 


W. N. Benson—Origin of Serpentine. 705 


other hand serpentines may occur in completely hydrated 
condition in the center of deserts (Merrill 1899, Holland 
1899). For this reason Merrill emphasized the ineffec- 
tiveness of atmospheric weathering, stating his belief 
that serpentinization is a deep-seated process due to 
waters coming from a considerable depth, which may 
even have been present in the parent magmas at the time 
of their intrusion. To the first part of this, Bonney has 
given his partial adherence (1899). Holland, rejecting 
atmospheric weathering as a cause of serpentinization, 
gave quite another explanation which is considered 
below. 


IV. The Source of the Water for Serpentinization. 


With the exclusion of surface water acting at small 
depths, from among the possible agents of serpentiniza- 
tion, attention must be directed to the deeper sources 
of water which may have effected the hydration of the 
intrusive masses. Four sources may be considered. 


a. Water diffused from the invaded rock in which it was origin- 
ally contained into the intrusive peridotite. 

b. Water forming portion of the underground circulation of 
at least partly epigene or meteoric origin. 

c. Water issuing from the ultrabasic magma itself during the 
last stage of its consolidation. 

d. Water issuing from magmas intrusive into or near the ultra- 
basic mass. 


a. Local diffusion of mterstitial water. 


The hypothesis of the production of serpentine by the 
diffusion into peridotite of the water contained in the 
invaded rock might explain the marginal serpentinization 
of intrusive masses, if there were to be considered only 
such masses as are intrusive into comparatively unal- 
tered sediments, with a high content of water. It is much 
more difficult to apply it in the case of large masses of 
serpentine that are intrusive into eneissic rocks such as 
thatin the Geisspfad Pass, and in the St. Gotthardt Tun- 
nel; and it is particularly difficult of application when 
the masses are almost completely serpentinized through- 
out, as in the case of that in the gneiss at Zoblitz in Sax- 
ony. In the last mentioned area, the serpentine, in such 
samples as have been seen by the writer in various 
collections or obtained by himself, exhibits the normal 


706 W. N. Benson—Origm of Serpentine. 


mesh-structure and are not schistose, so that their 
serpentinization must have followed the crushing to 
which the gneiss has been subjected, during which its 
water-content was probably greatly reduced. (See also 
Zirkel 1894.) It must be concluded that in general local 
diffusion is quite inadequate as a source of the water for 
serpentinization.? 


b. Water of the underground circulation. : 

That the water of serpentinization may be derived from 
the general deep underground circulation (probably the 
ascending portion) through the upper parts of the crust, 
has much more in its support, and is the hypothesis 
adopted by many writers explicitly (Van Hise 1904) or by 
implication. Since the freest channels for the ascent of 
the water might well be at the margins of the intrusive 
masses, the inward decrease of the degree of serpen- 
tinization might thus be explained, as well as the occur- 
rence of serpentinization along the fault and contraction- 
planes occurring within the mass, sometimes causing a 
banded structure in the serpentine. (Cf. e. g. Graham 
1917.) Moreover, as Van Hise explained, the upward- 
moving waters would be enriched in carbonic acid as a 
result of the silicification of carbonates in the deeper 
zones of metamorphism, and in this we may see the 
explanation of the strong attack of the waters upon the 
olivine and the subsequent carbonation of the serpentine. 
He added, however, that the effectiveness of circulating 
waters as metamorphic agents must be greatly increased 
by the addition to the general circulation in the middle 
zone of metamorphism, of waters of magmatic origin, 
though these probably form only a small portion of the 
whole supply. It is to the reactions in this zone of the 
character indicated that he refers the processes of ser- | 
pentinization and carbonation of the ultrabasic rocks 
(op. cit. pp. 608-612). Grubenmann’s reference of the 
formation of antigorite-serpentine and of tale-carbonate- 
schists to the uppermost of his zones of the crystalline 
schists is perhaps in accord with this view, though he 
adds that the ordinary massive or fibrous types of ser- 
pentine are best considered the product of weathering 

That serpentine itself may be diffused in solution throughout a rock- 
mass is assumed by Liesegang (1913) in his very interesting hypothesis 


of the development by diffusion of Eozoonal structures in magnesian 
limestones. 7 


W. N. Benson—Origin of Serpentine. 707 


(Grubenmann 1910). The extremely interesting dis- 
cussions recorded in ‘‘The Genesis of Ore Deposits’’ 
(Posepny Memorial Volume) show, however, that, in the 
opinion of several authorities, Beck, Launay, Lindgren, 
Rickard, Vogt and others, Van Hise has under-estimated 
the contribution made by magmatic waters to the general 
underground circulation. 

Holland (1899) has given a very special form to the 
hypothesis of the production of the great masses of ser- 
_ pentine by circulating epigene waters. While admitting 
the local action of magmatic carbonated siliceous waters, 
he points out that in the great geosynclinal regions of the 
world, the peridotites are almost always completely ser- 
pentinized, while in the continental massif of Peninsular 
India they are almost anhydrous, except for those parts 
that have been attacked by local magmatic waters (the 
evidence of this last is discussed below). From this he 
concludes that it is probable that advanced serpentiniza- 
tion results from an enhanced water-circulation brought 
about by the immersion of the land area beneath the sea; 
‘‘for if serpentinization is due to water coming from con- 
siderable depths, it is difficult to see why these rocks, 
erupted at different times, and in widely separated local- 
ities in Peninsular India, should universally escape, 
whilst in other areas, other serpentines aiso widely separ- 
ated by great distances, serpentinization is so constant. 
With the evidence of the action of deep-seated vapours in 
other ways in Peninsular India, the value of this point 
becomes accentuated.’’ But he adds: ‘‘Although the 
evidence, both positive and negative from India, indicate 
that a submarine existence has at some stage formed part 
of the history of every serpentine-mass, it will require 
the testimony of other areas to show that such submarine 
conditions are essential for serpentinization on an exten- 
sive sceale.’’ : 

The hypothesis is one that it is almost impossible to 
test satisfactorily. Holland draws attention to the belt 
of ultrabasic rocks on the eastern side of the United 
States, which are serpentinized in the northern portion 
over which the sea has transgressed at various times, but 
are practically anhydrous in the southern portions, pre- 
sumably crystallized under the same condition but which 
he believed were never covered by the sea. Schuchert’s 
recent series of paleogeographical maps (1910) confirm 


708 W. N. Benson—Origin of Serpentine. 


this opinion. Other regions yield less definite evidence. 
Thus the great continental block of Western Australia 
is invaded near its center by the thoroughly serpentin- 
ized rocks of Kalgoorli (Thomson 1913), Meetkathara 
(Clarke 1916) and elsewhere, which were not very likely 
to have been covered by more than a temporary extension 
of later Paleozoic or Cretaceous seas, and there is no 
proof that even these extended so far. The ultrabasic 
rocks of New Caledonia (Card 1900, Glasser 1903, 1904), 
New Zealand, and the Pyrenees (Bonney 1877, Lacroix ~ 
1890) though in geosynelinal regions, where intruded 
during the late Mesozoic or early Tertiary orogenic 
movement and have not certainly been flooded over by 
the sea in subsequent periods. ‘They are, as a rule, only 
-partly serpentinized. The peridotites of the Red Sea 
Hills in 8S. KE. Egypt are largely serpentinized, and it is 
possible, though by no means certain, that they may have 
been covered for a short time by the Cretaceous Sea. 
(Ball 1912). The ultrabasic rocks in the great conti- 
nental block of South Africa, namely those associated 
with the great norite dike of Rhodesia (Mennell 1910, 
Zeally 1915), or the Bushveld Complex (Henderson 
1898) have never been under the sea so far as can be 
ascertained and are only partly hydrous. The peri- 
dotites of Skye, which have probably not been covered 
by sea-water, are almost anhydrous, though their intru- 
sion has been followed by that of a series of magmas, 
gabbro, and granite, which however, do not elsewhere 
show much evidence of being greatly charged with mag- 
matic water (Harker 1905). 

Steinmann (1905) suggested that ‘‘The problematical 
process of serpentinization may be the result of the rapid 
cooling of an extremely peridotitic magma in the 
strongly cooled region below the sea, with the simulta- 
neous introduction of sea-water under high pressure,’’ 
an hypothesis suggested by the frequent association of 
serpentines with deep-sea marine sediments, but which 
can have no great bearing upon the development of ser- 
pentine that occurs among the gneisses. | 

If, however, we accept Holland’s general statement of 
the mode of occurrence as sufficiently accurate, it seems 
possible that it has another significance from that which 
he has ascribed to it. It may, perhaps, be stated as 
follows: In those regions in which the intrusive masses 
of peridotite have extended into the upper parts of the 


W. N. Benson—Origin of Serpentine. 709 


crust, into regions of lesser pressure, and there consoli- 
dated, they are now found generally serpentinized, while 
those which consolidated in the deeper parts of the crust, 
and are associated with crystalline schists (like the 
olivinites of Norway), have formed under heavy pres- 
sure, and are in general nearly anhydrous. The infer- 
ence from this would be that where there was available 
a supply of water to act upon the peridotite, hydration 
would occur down to such a depth that the chemical 
affinity of the olivine for water remained sufficient to 
overbalance the constraint exercised by the consequent 
expansion of the rock mass. In the deeper regions the 
Volume Law became paramount, and hydration with 
expansion could no longer occur. Anhydrous masses 
would remain at shallow depths, where for some reason 
there was no great supply of magmatic water, or where 
the water was enabled to escape, to higher levels, before 
it had thoroughly acted upon the ultrabasic rock. This 
possible source of water of serpentinization we now pro- 
ceed to discuss. 


cand d. Magmatic waters. 

While it is obvious, as Holland points out, that the 
occurrence of anhydrous masses of yperidotite raises 
difficulties in the way of the general reference of ser- 
pentinization to the action of magmatic waters, other 
difficulties appear if we must explain away the evidence 
in many localities pointing the action of such waters. 
This evidence is discussed below, but as very diverse 
features must be considered, a summary of the general 
argument will first be given, and the grounds which sup- 
port the several statements contained therein will be 
detailed later. The following appear to be the salient 
points :— 


i. Magmatiec waters, highly charged with silica and carbonic 
acid, ete., have been emitted in connection with certain 
peridotitic intrusions. 

li... Experiment shows that carbonated waters have a particu- 
larly strong solvent action on serpentine, and are able to 
attack olivine also. 

ii. Where magnesian rocks have been converted into tale and 
carbonates, this process occurred after they had been con- 
verted to serpentine, except in those cases where such 
change is demonstrably due to the action of atmospheric 
weathering. 


Am. Jour. Sct.—FourtH Serius, Vout. XLVI, No. 276.—DEcEmMBER, 1918. 
34 


710 W. N. Benson—Origin of Serpentine. 


iv. Though mesh-structure serpentine (chrysolite) is usually 
formed in regions of comparatively low pressure, and 
antigorite under high pressure, instances occur where 
antigorite has been formed by the recrystallization of 
mesh-structure serpentine. This is best explained by a 
recrystallization of the rock under an increased pressure 
in the one orogenic epoch of igneous activity, and it is 
unlikely that the solutions concerned in the process were 
of meteoric origin. | 

v. In some instances, after a rock had been more or less 
completely serpentinized, coarse-grained veins of antigorite 
and fresh glassy olivine have been formed in it, recalling 
in some measure the occurrence of pegmatite veins in 
granites. Such veins seem to be connected with others in 
the invaded rocks showing minerals usually indicating 
contact-metamorphism. 

vi. Serpentinization and carbonation have often been complete 
at the close of the orogenic epoch during which the 
peridotite was erupted. 

vu. But while serpentinization thus must have followed the 
intrusion of the -peridotite after a comparatively short 
interval, there have often (probably generally) been 
several intervening intrusions of differentiates of the 
magma that gave rise to the peridotite. This is shown by 
(a) the spatial relationship of the post-peridotitic intrusive 
masses to the development of serpentine; and, (b) alter- 
ation of masses intrusive into the ultrabasic rocks, which 
is of such a character as to indicate that the alteration 
of these later masses occurred during the process of ser- 
pentinization. 

vill. The process of serpentinization, if explicable as here indi- 
cated, is in some degree analogous to the process of grei- 
senization of granitic masses. It is probable that the 
carbonic acid at first acted as a catalyser, but subsequently, 
under cooler conditions, remained in combination with the 
magnesia. 


We now proceed to give the evidence for these several 
statements :— 


i. Holland’s investigations (1899a) of the magnesian 
rocks of the Salem District, Madras, show that they are 
locally altered to magnesite, and that ‘‘most, if not all 
the peridotites of Southern India are accompanied by 
masses and veins of pure white quartz, which always 
contain considerable quantities of liquid carbonic acid. 
The constancy of this association of peridotite with pure 
quartz, suggests a genetic relationship between the two.’’ 
The discussion of (iii) will show that similar action of 


W. N. Benson—Origin of Serpentine. (ast 


solutions of silica and carbonic acid upon ultrabasic 
rocks is of world-wide distribution. 

u. Clarke (1916) declares ‘‘that hydrous magnesian 
silicates are easily prepared by various wet reactions, but 
these syntheses have little or no significance in the inter- 
pretation of serpentine.’’ Nevertheless, Miller (1877) 
by acting upon olivine with carbonated waters, found 
that silica and magnesia were extracted therefrom in the 
right proportions to make serpentine. He also stated 
that serpentine was soluble in similar waters even at 
ordinary temperatures. Leitmeier (1913) has confirmed 
this, showing that 3-7% of finely powdered serpentine 
was dissolved in six months by weakly carbonated waters 
at 15°-18°C., and that magnesian carbonate and gelatinous 
silica were deposited. ‘This, he says, explains the forma- 
tion of opal which is frequently associated with car- 
bonated serpentines. What seems to be most desirable 
is that a series of experiments should be made upon 
the action of carbonated waters upon magnesian sili- 
cates at such pressures and temperatures that might 
more closely simulate the conditions under which mag- 
matic waters would act. We shall note below that other 
dissolved substances than carbonic acid may be instru- 
mental in serpentinization. 

ii. The development of magnesian carbonate rocks 
with tale, silica, etc., was studied by Schrauf (1882) on 
material from Bohemia. He concluded that the change 
was a continuation of the process of serpentinization, 
which he referred to the action of epigene waters 
enriched in carbonic acid by passage through the humus. 
The serpentinization of the peridotites was followed by 
carbonation, with the production of chalcedony or opal; 
and finally by the leaching out of the carbonates, leaving 

a siliceous skeleton. Such were the final stages of the 
af ae of the peridotites described by Pratt and 
Lewis (1905), who, however, recognized that serpentin- 
ization is not an essential preliminary to such atmos- 
pheric carbonation. Weinschenk (1894, 1913) referred 
the formation of breunnerite, associated with lime and 
magnesian silicates in the Tyrol, to an extension of the 
process of serpentinization, but considered this to be due 
to the action of post-voleanic waters. Schneider (1912) 
has adopted a third view, an extension of that of Schrauf, 
namely that both processes are to be referred to ‘‘secu- 
lar weathering,’’ as defined by Cornu (1910), which, so 


712 W. N. Benson—Origin of Serpentine. 


far as the writer understands it, appears to be similar to 
Roth’s conception (1869) of ‘‘complicated weathering,’’ 
a. €., the production of slow changes at depth by epigene 
waters, the chemical activity of which had been increased 
by the presence in solution of products of weathering 
obtained from the surface layers. Remarking that the 
width of the carbonate rock exposed in the St. Gott- 
hardt Tunnel is less than that appearing on the surface 
three thousand feet above, Schneider concludes that 
there is a gradual decrease in width of the carbonate zone 
with increasing distance from the surface. His observa- 
tion that the boundary between the serpentine and the 
carbonate rock is most irregular, weakens this conclu- 
sion, and, moreover, we have no knowledge of the width 
of the carbonate zone at intermediate, or lower, levels. 
(See figs. 1 and 2.) The rocks of this zone contain erys- 
talline carbonates of magnesia, iron and a small amount 
of lime, together with tale and chlorite. Redlich (1909), 
investigating the magnesite deposits of Kraubat, which 
form on serpentine or peridotite alike, concluded, how- 
ever, that, while the serpentinization may be the result of 
secular weathering (though antigorite has been formed) 
the carbonation is here the result of atmospheric weath- 
ering, since the magnesite is a gel, not a crystalloid, in 
this area (cf. Cornu 1910). In this condition the magne- 
site builds a thick earthy mass adhering to the tongue, 
and, microscopically examined, is seen to form isotropic 
flakes, which take a basic stain; but in the case described 
by Schneider the magnesite is a crystalloid in the usual 
rhombohedral form, and cannot be the result of atmos- 
pheric weathering according to Cornu’s criteria, though 
it may perhaps be the result of ‘‘secular weathering.’’ 
Schneider’s rocks are typical of very many occurrences of 
carbonates on the margin of serpentine-masses and, more 
rarely, as in the Bingara District, N. 8. W. (Benson 
1917), in bands within a mass of serpentine. In most 
of these, there is also quartz or chalcedony, residual or 
secondary (cf. Rosenbusch 1907) grains of chromite, and 
fuchsite, as e. g. at Kalgoorli, W. A. (Thomson 1913) ; 
sometimes sulphides are present. In the last region 
mentioned the structure of the carbonate rock renders it 
perfectly clear that the carbonation had occurred after 
the original rock. a poikilitic harzbergite, had been com- 
pletely serpentinized. 


W. N. Benson—Origin of Serpentine. 113 


Knopf (1906) found that the magnesian carbonate 
rocks of California had replaced peridotites, which were 
either quite fresh or were more or less serpentinized, and 
coneluded that the carbonation was a process distinct 
from hydration and subsequent thereto. Some lime and 
sulphide minerals were introduced during the change, but 
apparently no tale was formed. In other parts of Cali- 
fornia, the serpentine associated with the cinnabar 
deposits has been entirely removed by ‘‘solfataric 
agency,’’ and only the siliceous skeleton remains (Becker 
1888. See also Lindgren 1895, p. 153). Somewhat sim- 
ilar features have been observed by Lacroix (1897), 
as the result of the action on serpentine in Greece, of a 
fumarole, which exhaled carbonic and sulphuric acids 
and steam. Ferruginous honey-combed siliceous rocks, 
containing tale and breunnerite, are associated with ser- 
pentine in the northern part of the belt of magnesian 
rocks in Hastern U. S. A., and the several changes 
involved are considered to be the result of the action of 
the same agents as caused the serpentinization (Bascom 
1902, 1905). In the neighborhood of Madras, there are 
magnesite rocks derived from peridotites, by the action 
of magmatic waters bearing carbonic acid but, though 
Holland (1899a) concluded that the small amount of 
serpentine present was formed after carbonation, Mid- 
dlemiss (1896) held that serpentinization had preceded 
carbonation. 

The writer’s observations in New South Wales (Ben- 
son 1913) accord with this last. In several regions 
along the serpentine-belt, the rock is more or less com- 
pletely replaced by crystalline carbonates, tale, and 
quartz, chalcedony or opal. Generally this occurs on 
one side only of the serpentine mass, ‘‘the footwall,’’ 
occasionally in one or more bands within the serpentine, 
so that it would seem very probable that the carbonation 
is the effect of solutions moving in the thrust-planes 
that bound or traverse the serpentine. The location of 
the carbonated rocks is completely independent of the 
present topography, and there is clear evidence at 
Warialda, where the carbonated rocks are overlain by 
Jurassic sandstone, that the carbonation occurred before 
the sandstones were deposited (Benson 1917). The pres- 
ence of auriferous pyrites among the carbonated rocks 
gives further support to the hypothesis of the deep- 


714 W. N. Benson—Origin of Serpentine. 


seated origin of the carbonating solutions. Wilkinson 
(1885) referred to ‘‘geyser-action’’ the formation of the 
sinter-like siliceous rocks occurring at Hanging Rock in 
the Nundle District, but the persistence of the occurrence 
of the partially leached and more or less sinter-like 
siliceous rocks here and there throughout the whole 
length of the serpentine belt (over two hundred miles), 
leads one to the belief that, while the production of the 
ferruginous sinter from the siliceous carbonate rocks 
may be merely the effect of surface-waters, the waters 
that formed the main mass both of the serpentine and 
of the carbonate rocks were either genetically directly con- 
nected with the great intrusive mass of peridotite itself, 
or were those which also formed the auriferous quartz 
veins, occasionally containing pyrites and calcite, that 
traverse the sedimentary and igneous rocks invaded by 
peridotite. These veins seem to have been formed at 
some rather indefinite time during the long period of 
plutonic igneous activity which followed the intrusion of 
the peridotites (middle Carboniferous) and ended with 
the intrusion of granitic rocks before the commencement 
of Mesozoic time, and it would be in accord with the views 
of perhaps the majority of modern geologists to consider 
that such vein-forming waters were derived in part at 
least from plutonic sources, and thus indirectly from the 
same magma which gave rise to the peridotite. The 
highly undulose extinction of the quartz formed in these 
siliceous carbonate rocks may indicate that they suffered 
considerable strain, presumably in the orogenic epoch in 
which these intrusions occurred; though it may perhaps 
have resulted merely from the strains that might be 
set up in quartz, forming from opal by dehydration. 
The point is, that if the carbonation was performed by 
the magmatic waters, it follows almost necessarily the 
preceding serpentinization was also. 

Similar carbonate tale rocks occur in New Zealand, and 
are especially well developed near Hokitika, where they 
contain numerous cubes of pyrites. Bell’s description 
(1906) indicates that they are closely similar to the 
ereisen-like pyritic carbonate rocks of the Nundle Dis- 
trict, N. S. W., and Dr. Bell adds: ‘‘the presence of so 
much pyrites indicates considerable solfataric action fol- 
lowing or during the period of Poumanu (1. e. ultrabasic) 
intrusion.”’ 


It 


W. N. Benson—Origin of Serpentine. 71 


In some regions there is evidence that the peridotitic 
intrusions were accompanied or followed by the emission 
of volatile substances such as are usually associated with 
granitic masses. Thus Bell (1907) found tourmaline in 
the serpentinous schist in the Parapara District, N. Z.; 
Dupare and Sigegs (1913) found it in the serpentine of the 
Urals, and Lacroix (1894, 1901, 1914) found it in associa- 
tion with scapolite in caleareous rocks invaded by the 
peridotite of the Pyrenees. His first memoir (1894) 
describes and discusses a large amount of evidence of 
this action. 

Occasionally there is also evidence of the expulsion of 
sodic solutions from the peridotitic magmas, which is 
perhaps connected with the development of albitic veins 
in these rocks, to the widespread occurrence of which, the 
writer has already drawn attention (Benson 1918). 
Thus Park (1908), citing analyses by Maciaurin, shows 
that of two otherwise closely analogous mica schists, the 
one adjacent to the margin of a mass of serpentine at 
Cromwell, N. Z., contained 8-:07% Na,O as compared with 
but 2:91% in that two yards from the contact. The well- 
known glaucophane-schists near the serpentine masses of 
California first described by Ransome (1893) are some- 
times cited as an example of this, though doubt has been 
thrown on their development as a result of contact met- 
amorphism (e. g. by Nutter and Barber 1902). The 
occurrence of scapolite in the neighborhood of the Lac 
du Lherz, as mentioned by Lacroix, recently redescribed 
by Longchambon (1910-1911),? may be a further example 
of the emission of soda. Thus we see that associated with 
the peridotitic intrusions, there are magmatic waters 
that are charged with carbonic acid and silica, and 
sometimes with hydrogen sulphide, boric acid, hydro- 
chlorie acid, and soda. Nevertheless the metamorphic 
action of these magmas is, as is well known, much less 
marked than that of the more acid rocks. 


*'This paper is interesting as an instance of the application of the 
special views of a school of French petrologists in regard to the relation 
of metamorphism, melting down, and mixture of sediments and the fea- 
tures of ‘‘the chemistry of the geosyncline’’ to the origin of ultrabasic 
rocks. Lherzolite according to this discussion is produced in a manner 
following ‘‘the general equation granitic magna plus dolomite — CO, plus 
basic magnesian silicates plus pegmatitic fumaroles.’’ The last term 
includes inter alia the emission of sodie solutions from the basic magmas. 
A rather different hypothesis is expounded by Termier (1903). 


716 W. N. Benson—Origin of Serpentine. 


iv. Grubenmann, voicing an opinion held by numerous 
petrologists, has stated that while antigorite is a product 
of hydration under pressure and formed in the upper 
zone of metamorphism, normal mesh-structure chrysotile 
Serpentine is a product of weathering (Grubenmann 
1910). One might infer from this that in any rock, con- 
taining the two forms of serpentine, antigorite would have 
been formed first at a great depth, and mesh-structure 
chrysotile would be developed from the residual olivine, 
when under lesser pressure and at a smaller depth, the 
rock came under the influence of meteoric waters. 
Weinschenk (1913), on the other hand, weuld divide the 
process into: (a) the formation of primary antigorite in 
the rare instances in which it occurs; (b) the formation 
of secondary antigorite by the action of magmatic waters 
upon the residual olivine; (c) the formation of veinlets of 
olivine and antigorite crystallizing from the magmatic 
water; and (d) finally the formation of mesh-structure 
serpentine from the residual olivine as last effect of the 
thermal waters. 

In both hypotheses, antigorite is of earlier formation 
than mesh-structure serpentine. Nevertheless the writer 
has found that this is not always the case. It was seen 
that in certain serpentines from New South Wales that 
mesh-structure serpentine may reerystallize into anti- 
gorite serpentine, the long blades of which le in positions 
quite without relation to the position of the secondary 
magnetite, which separated out from the olivine as it 
formed by its first change into chrysotile-serpentine, and 
still exhibits the characteristic mesh structure. The pro- 
cess was traced through a series of slides which exhibited 
all intermediate stages. In serpentines in which the 
antigorite comes directly from the olivine (or pyroxene) 
the magnetite is often in little triangular patches, inter- 
stitially placed among the laths of antigorite, and recall- 
ing the intersertal and occasionally the ophitice structure 
of dolerites (cf. Bonney 1905), but in the serpentines in 
which the antigorite has formed after the change to 

chrysotile, the magnetite remains in fine dusty particles. 
Dr. Flett, who kindly examined the series of slides in 
question, expressed his concurrence in the interpretation 
placed thereon.* Similar evidence of the replacement of 
mesh or chrysotile serpentine by antigorite was seen in 
a specimen from Visp, Switzerland, described by Preis- 


* (Letter to writer, 2:5:1913.) 


W. N. Benson—Origin of Serpentine. 717 


werk (1903) who has generously permitted this mention 
of a feature in his slide not previously noted, and also his 
concurrence in the interpretation here suggested. Sev- 
eral slices of the serpentines of the Gross Venediger 
Stock, Austrian Tyrol, described by Weinschenk (1894) 
seemed to the writer to be capable of a similar inter- 
pretation. They appeared to show the development of 
secondary magnetite in mesh-like bands of minute grains, 
between the residues of the olivine and pyroxene erystals, 
but these have been slashed across by blades of antigorite 
in the usual manner, while antigorite completely replaces 
the first formed chrysotile. Professor Weinschenk 
verbally informed the writer that analogous features are 
present in some of the serpentines of Wurlitz, near Hof, 
in the Fitchelgebirge, but while kindly permitting the 
publication of this suggestion, does not himself accept it. 
Hence these cannot be cited as indubitable examples of 
the change here suggested. 

This structural change in serpentine has apparently 
been observed by Bonney (1908), for he remarks that, 
while few of the antigorite serpentines studied by him 
contain any residual olivine, in a few the matted antigo- 
rite is traversed by tiny strings of opacite resembling 
those in a serpentine formed from that mineral. 

With regard to the general question of the origin of 
antigorite, a few words may be given. Weinschenk him- 
self states that the formation of primary antigorite is 
very rare; and, though his hypothesis has been fre- 
quently tested since it was announced, few instances 
have been found which seemed to eall for this explana- 
tion. Krotov (1910) and Granageg (1906) have accepted 
the hypothesis of the primary crystallization antigorite, 
as best explaining the features of serpentines in the 
Southern Urals and Carinthia, but reasons given in each 
ease, the former certainly in abstract only, do not seem 
quite convincing. On the other hand, Bonney (1914) has 
decisively rejected the hypothesis. After a study of 
some of the original material from the Gross Venediger 
Stock, by kind permission of Professor Weinschenk (who 
has most clearly and fully described the features devel- 
oped), the writer could not feel completely convinced of 
the necessarily primary origin of the antigorite in the 
very remarkable slides that he saw. He could not go 
beyond the cautious comment of Harker (1897) that, 
‘‘though the reasons for regarding the antigorite as an 


718 W. N. Benson—Origin of Serpentine. 


original mineral do not seem to be perfectly convincing, 
the phenomena described are sufficiently remarkable to 
deserve careful consideration. ’’ 

v. One of the most remarkable features described by 
Weinschenk was clearly illustrated by the material 
shown to the writer in Munich. There seems no possi- 
bility for doubting that, in the case of the slides exam- 
ined, the rock had been completely changed to serpentine 
before the formation of numerous cracks, which were 
filled by very coarse-grained antigorite intergrown with 
glassy clear olivine, and sometimes with magnesite. The 
very coarseness of the grain size compared with that of 
the main mass of the rock suggests a comparison with 
pegmatite, forming from the residual mother liquor of 
the magma; and according to Weinschenk, where these 
veins extend beyond the ultra-basic rock into the sur- 
rounding calc-schists, they are associated with vesuvi- 
anite, garnet and other minerals of contact metamorph- 
ism, which seems to give further indication of their 
magmatic origin. We may, therefore, concur in the 
view that the antigorite is here of hydrothermal origin, 
forming at or before the close of the period of igneous 
activity, which produced the peridotites. It must surely 
follow that the prior serpentinization of this peridotite- 
mass took place at such a depth as almost to exclude the 
action of meteoric waters, and while large amounts of 
magmatic water were present. 

These interesting veinlets containing olivine travers- 
ing serpentine are not without analogy, for similar fea- 
tures have been noted by Palache (1907), who found a 
narrow sharply-defined vein of glassy clear olivine two 
inches in width in the ‘‘platey serpentine’’ of Chester, 
Mass., U. S. A., which had replaced olivine 'and pyroxene. 
It is here also clear that the serpentine formed before the 
intrusion of the olivine vein. 

A possible objection to the hypothesis of the produc- 
tion of olivine by erystallization from a hydrous mag: 
matic solution is that as yet it has been formed artificially 
by methods of dry-fusion only. Nevertheless, the pro- 
duction of olivine in magnesian limestone at granite 
contacts is well known, and here the action will be prob- 
ably a pneumato-hydrothermal one. In any case, the 
possibilities of experimentation with carbonated solu- 
tions under conditions of high temperature and pressure 


° But see Rosenbusch’s alternative suggestion, p. 722. 


W. N. Benson—Origin of Serpentine. 719 


have been scarcely investigated, much less exhausted. It 
is interesting to note again in the Tyrolese instance the 
presence of carbonates in the olivine-antigorite veins 
that traverse the serpentine. 

vi. Where geological evidence is available of the 
period of hydration, the serpentine seems to have been 
formed at a comparatively short time after the intrusion 
of the ultrabasic rock. It is true that Crosby (1914) 
considers that serpentinization of ancient peridotites 
may be even now in progress at some depth in the earth, 
and suggests that the high frequent relief of such ser- 
pentine masses may be due to the steady upthrusting of 
the rock, as it expands during combinaticn with circulat- 
ing waters in the crust; but this explanation of the relief 
of serpentine areas seems unnecessary. It has long been 
recognized that the chemical stability of the serpentine 
molecule gives it great power of resisting weathering, 
though the rock yields readily to erosion. (See e. g. Hunt 
1883.) If we study the conglomerates that were formed 
shortly after the intrusion of ultrabasic rocks, we find 
that sometimes they contain pebbles of normal serpentine, 
so similar to that occurring in the great rock-masses 
from which they were derived, that it is scarcely possible 

that they could have been formed under different condi- 
' tions, the one as a large deep-seated plutonic mass of 
peridotite, the other as a pebble of peridotite included in 
a conglomerate, where it would encounter strongly ox1- 
dizing waters. It is therefore most probable that the 
plutonic mass had been hydrated to serpentine before the 
pebble was torn from it. As instances the following may 
be cited: Serpentine-pebbles appear in the Silurian 
rocks near Ballantrae in Scotland, derived from ultra- 
basic rocks intrusive into the Ordovician rocks (Peach 
and Horne 1897). A pebble of serpentine, probably 
derived from the peridotite that was intruded in Middle 
Carboniferous times, occurs in the lower Permo-Carbonif- 
erous beds of New South Wales (David 1907). It is 
quite clear that the carbonation of the Carboniferous ser- 
pentine in the Warialda District of New South Wales 
occurred before the deposition of the overlyimg Juras- 
sic sandstone (Benson 1916). The ultrabasic rocks of 
Upper Jurassic age have furnished the bowlders of ser- 
pentine which form a great part of the Middle Creta- 
ceous series of Bosnia. [Such at least is Katzer’s view 


720 W. N. Benson—Origin of Serpentine. 


(1903), but there is a divergence of opinion on this point. 
See alternatives suggested by Mojsisivies, Tietze, Bitt- 
ner and Kispatic, summarized by the last named (1900).] 
Otis Smith (1904) has also drawn attention to this fea- 
ture pointing out: its bearing on the hydrothermal origin 
of serpentine. He noted that the basal Hocene conglom- 
erates, lying on the serpentines of the Mount Stuart 
Complex in Washington, U. S. A., contain pebbles of ser- 
pentine exactly similar to that of the serpentines of the 
complex itself. Though the age of these serpentines is 
indefinite, it is probable that they belong te the general 
series of ultrabasic rocks that were formed during the 
late Mesozoic orogenic movements in western U. S. A. 

All of these observations confirm Weinschenk’s state- 
ment (1894) that the serpentinization has been completed 
by the end of the orogenic epoch in which the peridotite 
was formed. | 

vu. But although cumulative evidence thus points to 
the serpentinization by magmatic waters during the same 
orogenic epoch of vulcanicity as produced the peridotite, 
it does not appear that this followed directly after the 
ultrabasic intrusion, and without further magmatic-dif- 
ferentiation. Indeed, in many cases it seems that the 
peridotite remained anhydrous while several later intru- 
sions of magma occurred, before expulsion of the residual ~ 
magmatic water. In the case of the serpentine of the 
Lizard, Flett and Hill have concluded (1912) that the 
hydration of the peridotites occurred at a ‘‘compara- 
tively late period in their history,’’ at least after the 
intrusion of the veins of gabbro; Bonney (1914) concurs 
in this. The serpentines in the Ivrea Zone, northern 
Italy, are by Novaresse (cited by Rosenbusch 1907) 
referred to the after-action of the diorites upon perido- 
tites, while in numerous cases serpentinization is consid- 
ered to be the effect of magmatic waters accompanying 
the intrusion of granite as the latest differentiate from 
the same magma as gave rise to the peridotites. Thus 
Low (1906), Barlow (1910), Diller (1910), and Dresser 
(1913), conclude that the hydration of the peridotite in 
the regions studied by them (eastern Canada and Ari- 
zona), was brought about in a large measure by mag- 
matic solutions derived from intrusions of granite in or 
near the serpentine masses, stating that hydration is 
most complete in the vicinity of the granite. This view 


W. N. Benson—Origin of Serpentine. 721 


is also adopted by Graham (1917), who argues that the 
solutions were not carbonated but merely silicic, since 
there is a noteworthy absence of any carbonates, and it 
seems improbable that an amount of carbonate in bulk 
from a quarter to a twelfth of the volume of serpentine 
could have been removed in solution. Dr. Bell thinks 
that the hydration of the dunite in the Parapara District, 
N. Z., may be the result of thermal waters accompanying 
the acid intrusive rocks which are associated with the 
ultrabasic rocks (Bell 1907), but there is no suggestion 
of the presence of such rocks in the quite similar serpen- 
tines of the Hokitika District (Bell 1906). Otis Smith 
(1904) has suggested that the serpentinization of the 
peridotites in the Mt. Stuart district, Washington, 
U.S. A., was effected by magmatic waters emitted from 
the mass of granodiorite by which they have been 
invaded, but again the presence of such invading masses 
is by no means a constant feature in the occurrences of 
serpentine along the Pacific slopes of the United States. 
The continuous zone of serpentine between the dunite 
and the pyroxenite of the Tagil complex in the Ural 
Mountains (see fig. 4), as shown in Wyssotzky’s care- 
ful map (1913), may illustrate another instance of this 
mode of formation, though it must be noted that here it 
has been suggested that the pyroxenite is a differentiate 
formed im situ, and simultaneously with the dunite, 
rather than a latter intrusion. The same suggestion has 
been made in Tasmania, by Waterhouse (1916) in the case 
of the Heemskirk District, where there have been both 
gabbro and granite intrusions following the peridotite in 
the one igneous epoch, and it has also been urged by Mr. 
Twelvetrees (1917) in explanation of the serpentines of 
Anderson’s Creek, which have been invaded by granite. 
In the last two cases there is a large development of 
eranite with the serpentine, but in others as Graham 
remarks (1917) ‘‘it may be objected that the number and 
size of the exposed granite dykes and masses are totally 
inadequate to have been responsible for serpentinization 
on the scale which has actually occurred’’; but he sets 
the objection aside as based merely on a matter of opin- 
ion as to the amount of water that might accompany a 
eranite-intrusion. There is also to be considered the 
possibility of the occurrence of large unexposed masses 
of granite where but few veins are visible. In the Great 


{22 W. N. Benson—Origm of Serpentine. 


Serpentine Belt of New South Wales, the objection is a 
rather cogent one, for the acidic veins are very rare, and 
the degree of serpentinization is entirely independent of 
the proximity of the great batholiths of granite, which 
invade the serpentine at one place, at others are twenty 
miles distant (see maps Benson 19138, 1916). It would 
be of interest to test this point in the great mass of only 
partly hydrated ultrabasic rocks in New Caledonia, 
where there does not seem to be any large amount of 
rock less basic than the peridotites. Lacroix (1911) has 
noted the occurrence of veins of pyroxenite and anortho- 
site, and Card (1900) of gabbro and diorite, but appar- 
ently these occur only in small quantity. There also 
occur small areas of granite in the serpentine, but it is 
not clear that they invade it (Glasser 1903, 1904). 

A feature emphasized by Graham (1917) is of interest 
us affording another indication that serpentinization may 
follow the invasion of a series of gabbros into peridotites. 
Where these rocks contain monoclinic pyroxene, lime and 
more or less alumina must be set free during serpentin- 
ization; to this process is attributed the formation of 
grossularite (or topazolite), vesuvianite, epidote, zoisite, 
and diopside in veins in and near the serpentines. Other 
lime-silicate veins, somewhat analogous to these, were 
found in association with serpentine in the Tyroi by 
Weinschenk (1894), in Roumania by Murgoci (1900), in 
Italy by Novarese (vide Rosenbusch 1917, ‘‘garnet- 
ites’’); Kalkowsky (1906) also notes them as occurring 
in Liguria, Judd (1895) and the writer (Benson 1913) in 
New South Wales, Ward (1911) and Waterhouse (1916) 
in Tasmania. Such rocks have been variously inter- 
preted; Weinschenk (1894) referred them to the inter- 
action of magmatic waters derived from the peridotite 
(not from a latter differentiate) upon the chloritic cale- 
schist into which it had been thrust, thougn the adjacent 
central-granites, which Weinschenk considers to have 
also crystallized from a very aqueous magma under 
pressure, are considered by some writers to be of more 
recent origin than the peridotites, and to invade them in 
at least one spot (Becke and Léwl 1903). Rosenbusch, 
after an examination of Weinschenk’s material, con- 
siders that at least part of it is a highly altered schistose 
gabbro, or allalinite (Rosenbusch 1907), and that the 
change in this case was effected without noteworthy chem- 
ical variation. Murgoci (1900) found included in the 


| 
/ 
: 
; 


W. N. Benson—Origin of Serpentine. 723 


Paringti serpentine, masses of diopside, diallage, with 
grossularite, vesuvianite, fassaite, clinozoisite, lotrite (a 
form of prehnite), clinochlore, apatite, ilmenite, rutile 
and sphene. He concluded that the more coarsely gran- 
ulitic masses, with an appearance like that of saussurite- 
gabbro, were indeed an altered form of gabbro, but that 
some hornstones of similar mineral composition were 
altered inclusions of chloritic cale-schist. The writer has 
found that in the serpentine of the Bingara region, 
N. 8. W., there are numerous masses of pale green or 
white grossularite rocks, and that every stage can be 
noted in the change from gabbro with 15-8% CaO anda 
specific gravity of 2-93 to a grossularite rock with 33:3% 
CaO and a specific gravity of 3:42. The development of 
prehnite is often quite considerable. If it be, as seems 
probable, that the addition of lime was obtained during 
the process of serpentinization, we could here conclude 
from this mineralogical change that the peridotite had 
not been hydrated at the time of the intrusion of the gab- 
bro, just as in the case of the Lizard rocks. The Tasma- 
nian lime-silicate rocks are ascribed by Ward (1911) and 
Waterhouse (1916) to the ‘‘chemical reaction of the 
emanations from the acid magma-hearths upon the walls 


of the fissures that traverse the basic-rocks.’’ 


Steinmann (1908), while elaborating his view that 
nephrite masses are formed from originally continuous 
dikes of websterite, broken and metamorphosed during 
the serpentinization and expansion of the including 
masses of peridotite, states that the copper veins in the 
serpentine have also been dislocated by the expansion, 
the effects of the pressure varying so much locally that 
it can hardly be the result of orogenic movement alone. 
He adds that wherever the evidence is clear one can 
prove that the peridotite was still anhydrous when it was 
invaded by gabbro, indeed sometimes it seems probable 
that it was still hot. From this he infers that the pro- 
cesses of serpentinization, and of the nephritization and 
saussuritization connected therewith, commenced only 
after the vulcanicity had been so far exhausted that ore- 
formation had occurred, but, on the other hand, that the 
processes had been completed before the last stage of the 
orogenic epoch that commenced with the intrusion of the 
peridotite, and ended with great overthrustings. Fin- 
layson (1909), referring to the serpentines and peri- 
dotites of Dun Mt., N. Z., in which there occur sulphidic 


724 W. N. Benson—Origin of Serpentine. | 


copper ores, stated: ‘‘Processes of hydration, which 
appear to have been concentrated chiefly in the neighbor- 
hood of the belt of sulphides, and to have acted with 
diminishing intensity towards the other side of intrusion, 
have resulted in the serpentinization of the olivine rocks 
with the exception of the residual mass which composes 
the summit of Dun Mountain. Subsequent alterations, 
due to dynamic agencies, have resulted in the develop- 
ment of uralite, saussurite, and antigorite.’’ Speaking 
generally of the serpentines throughout New Zealand he 
said: ‘‘It is noteworthy that the most highly serpentin- 
ized occurrences are associated closely with evidences of 
considerable solfataric action. Thus the sulphide zone at 
Dun Mountain is perfectly serpentinized, and the serpen- 
tines of the Hokitika area are likewise associated with 
solfataric effects. Where such action has been wanting, as 
around the dunite of Nelson and at Milford Sound, ser- 
pentinization is absent, although the rocks have been 
much crushed by pressure and movement. The study of 
the processes of serpentinization strongly suggests that 
hydrothermal action, during and following the intru- 
sions, has been a potent factor of serpentinization.’’ At 
the same time it must be noted that this assumes the mag- 
matic origin of the cupriferous solutions, which brings 
in once more the vexed question of the relative importance 
of magmatic solutions as compared with lateral secre- 
tion in the production of ore bodies. While the magmatic 
solutions are perhaps most generally credited with the 
predominant réle, there are strong opponents of this; e.g. 
Van Hise (1904, pp. 1043-1081 and numerous citations), | 
who, however, refers to a matter of particular interest 
in this connection, namely the occurrence of high-grade 
copper sulphide ores in the serpentinized peridotites of 
Tuscany and Liguria, described by Lotti (1899), and held 
by Vogt to be of indubitably magmatic origin (Vogt 
1902). They were later described by Delkeskamp (1907). 
Other occurrences of copper ores in serpentine are 
noted by Weed and Beck. (See under Lotti 1899.) 


V. The Formation of Nephrite. 


The close association of nephrite with serpentine is 
very often observed, and without doubt there is a genetic 
connection. Though the writer has not studied in detail 
the extensive literature on the formation of nephrite, a 


ky 


W. N. Benson—Origm of Serpentine. 125 


few views may here be noted for the bearing they may 
have on the origin of serpentine. Kalkowsky (1906) 
noted the occurrence of nephrite in Liguria, a rock rather 
than a mineral, associated with talc, serpentine and ecal- 
eite in the neighborhood of faults and dislocations. He 
considered it to be formed under deep-seated condi- 
tions by pressure metamorphism of the tale-serpentine- 
carbonate rocks. He described specimens of nephrite, 
which he considers to be pseudomorphous after chryso- 
tile and after tale. Steinmann investigated the same 
occurrences as were described by Kalkowsky (1908) and 
his view is cited above, and concurs with the earlier 
hypotheses which referred the formation-to a process of 
uralitization. Finlayson considered that both these pro- 
cesses may have given rise to nephrite in New Zealand, 
and adds another method, namely a direct transforma- 
tion of olivine into nephrite. Bonney, however, saw 
difficulties in this last and especially in the derivation of 
nephrite from talcose rocks, believing that the reverse is 
more probably the case. The derivation by uralitization 
appears to be unchallenged (Finlayson 1909 and dis- 
eussion), and this is held to be a deep-seated process 
associated with dynamic action.® 


VI. The Occurrence of Serpentine in Volcanic Rocks. 


Obviously, any consideration of the origin of the min- 
eral serpentine should include a consideration of the 
conditions of its occurrence in volcanic rocks. This 
would require a lengthy personal investigation into the 
microscopical and field-characters of the basic lavas, 
which as yet the writer has been unable to undertake. 
In the literature there are very frequent statements that 
the olivines of basalts have been serpentinized, and that 
owing to their ferriferous character, the serpentine is 
pleochroic. Sometimes the occurrence of a platy pleo- 
chroic ‘‘serpentine’’ is noted, and referred to iddingsite, 
considered to be a ferriferous variety of antigorite, and 
Uhlemann (1909) gives an elaborate account of the 
formation by weathering of iddingsite as a ferruginous 
form of antigorite in the picrites of Saxony, drawing 
comparisons between this and the features described by 
Weinschenk. Nevertheless, a close inspection of all 
examples of altered olivine encountered by the writer in 


°*But see Dupare et Hornung. 1904. 


Am. Jour. Sct.—Fourta Series, Vovt. XLVI, No. 276.—DEcEMBER, 1918. 


726 W. N. Benson—Origin of Serpentine. 


volcanic and other rocks, causes him to view with some 
caution the frequent statements of the presence of ser- 
pentine as a product of weathering. Under the term ser- 
pentine in its restricted significance, we are here consid- 
ering only those forms of chrysotile and antigorite as 
are considered e. g. by Bonney (1905). Such minerals 
when examined microscopically are nearly colorless, and 
have a double refraction not greater than -013. Many, 
perhaps the majority of writers, however, include also 
under the term serpentine various more or less deeply 
colored and pleochroic minerals, with fibrous or platy 
habit and a double refraction nearly twice as great. 
Thus Teall (1888, p. 189) refers to ‘‘a rich deep green 
serpentine.’’ A study of Lacroix’s collection in Paris, 
illustrating his Mineralogie de la France et ses Colonies, 
showed that this colored fibrous form is the mineral he 
classes as bowlingite, and considers to be merely the 
fibrous form of the platy pleochroic mineral iddingsite, 
and also places it with the serpentine-minerals. Wein- 
schenk (1907) coneurs and refers to it merely as a ferru- 
ginous form of serpentine. So also does Harker (1904), 
who carefully distinguishes between the effects of mag- 
matic water upon a basalt (the production of zeolites, 
etc.), and that of true weathering, the ‘‘serpentiniza- 
tion’’ of the olivine. The serpentinous material pro- 
duced is described as being of a pale green color, and 
associated with a micaceous substance which forms the 
bulk of the pseudomorphs and is comparable with idding- 
site. These pseudomorphs may re-absorb part of the 
secondary magnetite, and become deep green in color and 
strongly pleochroic (op. cit. p. 35). In gabbros from the 
same region (Skye) he has noted that complete destruc- 
tion of the olivine gives rise to pseudomorphs of green 
and yellow-brown serpentine, the secondary magnetite 
being here also absorbed, while pilitic pseadomorphs and 
iddingsite may occur. The writer has observed a block 
of dunite in a volcanic breccia, partly changed into nor- 
mal chrysotile-serpentine and secondary magnetite, trav- 
ersed by a band an inch in width composed entirely of 
bowlingite, with no secondary magnetite, but preserving 
the outlines of the olivine crystals. In this instance it 
seems likely that the fragment of dunite was a homo- 
geneous or cognate xenolith in a basaltic breccia, that it 
was partially serpentinized at depth, and later torn from 
its position, included in the breccia, fractured, and altered 


W. N. Benson—Origin of Serpentine. 127 


along the crevice by circulating partly meteoric waters 
acting at no great depth. (This conclusion is based on a 
re-examination of material previously described. Ben- 
son 1910.) The distinction between the colored pleo- 
chroic minerals without secondary magnetite, and the 
colorless minerals with secondary magnetite produced 
from the same rock, is so clear that the conditions of 
formation of the two can hardly be the same. We may 
freely admit that iddingsite and bowlingite are the 
products of true weathering, but there does not seem to 
be sufficient evidence to refer the formation of antigorite 
or chrysotile to the same process. For this reason the 
writer doubts the propriety of considering iddingsite to 
be a ferruginous form of antigorite, owing to the differ- 
ent mode of occurrence. It would be interesting in this 
connection to study the changes of olivine in lavas acted 
upon by solfataric waters, though on general consider- 


_ations the presence of abundant oxygen and the absence 


of any noteworthy pressure would probably result in the 
action being an intensified process of weathering. 


VII. Summary and Conclusions. 


The various lines of inquiry we have endeavored to 
follow support the general view in regard to the large 
ultrabasic masses that the chrysotile or antigorite-ser- 
pentine of which they are composed is an alteration 
product of an originally intrusive peridotite, often more 
or less pyroxenic, and that in some cases at least the 
hydration was brought about by the agency of waters 
emanating from the same magma that produced the 
peridotite, though not generally until a considerable 
amount of further differentiation has taken place. The 
change was, however, completed by the end of the one 
orogenic period of vulcanicity. We have yet to explain 
satisfactorily the absence of hydration in certain cases.” 

It is not so clear that a peridotite which has escaped 


7 As a suggestion to this end alternative to that previously advanced, pp. 
707-8 we may note Van Hise’s view (1904, p. 350): ‘*‘ Alterations of ser- 
pentine in the zone of anamorphism are not recorded. But the general 
absence of serpentine in the schists and gneisses of sedimentary origin 
profoundly metamorphosed in the zone of anamorphism is conclusive evi- 
dence that the serpentine that was once in these rocks, and the associate 
secondary minerals, have recombined to produce heavy minerals of the 
classes from which the serpentine and those other secondary minerals were 
originally produced.’’ This recalls Stapff’s hypothesis of the origin of 
olivine from serpentine, but does not seem to the writer to be convincing, 
since it assumes without proof the prior development of serpentine. 


728 W. N. Benson—Origin of Serpentine. 


hydration during the igneous epoch can subsequently 
become changed to serpentine by the action of deep cir- 
culating epigene waters, though it seems not improbable. 
Very frequently the hydration and carbonation has 
caused the development of concentric zones about the 
ultrabasic mass; in such cases the outermost is tale and — 
carbonates, the inner is serpentine, and the center anhy- 
drous dunite. This recalls the development of greisen 
about some but not all granite-masses, and in these the 
outermost portions, which have been longest and latest 
acted upon by the outward-passing volatile matter, show 
the change most completely. This, however, is perhaps 
the explanation only in those cases if any in which the 
hydration can be referred definitely to the action of 
waters actually proceeding from the ultrabasic magma; 
in others, in which the water of hydration has been 
derived from a latter magmatic differentiate, or perhaps 
from the general underground circulation, we must con- 
ceive of the peripheral alteration as the result of a type 
of centripetal diffusion of solutions. 

It would be wrong in putting forward the evidence for 
the significance of magmatic waters in the production of 
serpentine, though it is widely accepted, to overlook the 
fact that it is not accepted by certain geologists, who have 
had very great experience of this rock, and have con- 
cluded that the change of the anhydrous silicate is so 
capriciously localized that it should be regarded rather as 
the result of the ordinary change of a mineral very sus- 
ceptible to the action of water. But while not ignoring 
this objection, or denying the possibility that the change 
may have been sometimes effected by waters other than 
magmatic, the writer hopes that by this putting together 
of the evidence that much of the serpentinization is per- 
formed by water of magmatic origin some service may 
be rendered to other students of this interesting and dif- 
ficult problem. It may be strongly urged in conclusion, 
upon those whose laboratory facilities permit of such 
work, that much useful information might be obtained 
from the experimental investigation of the action of car- 
bonated waters and other energetic solutions upon mag- 
nesian silicates at high pressures and temperatures, for 
this seems essential for the final solution of the problem. 

The writer’s thanks are due Professor Bonney, Dr. 
Harker and to many other friends, teachers and students, 


WN. Benson—Origin of Serpentine. 729 


in the various institutions visited, for their generous 
loan of microscopic slides, and the helpful discussion 
of the points connected therewith. This help has been 
partly acknowledged as occasion arose in the body of the 
paper. He is also indebted to Dr. Flett for his guidance 
over the Lizard District, and for much help and encour- 
agement. 


List of Papers cited. 


In some cases the contents of the papers cited have 
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These have been indicated by an asterisk in the list 
below. 


Ball, 1912. The Geography and Geology of South-eastern Egypt. Sur- 
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*Barlow, 1910. Notes on occurrence of asbestos, J. Canadian Mining 
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Bascom, 1902. Geol. Survey of Maryland, pp. 95-134. 

1905. Bull. Geol. Soc. America. 

Beche, De la, 1831. The Geological Manual, p. 481. 

Becke, 1894. Min. petr. Mitth. 14, p. 271. 

Becke and Lowl, 1903. Congrés Geol. Internat., Vienna. 

Becker, 1888. U.S. Geol. Survey, Monograph 13, 1888. 

Bell, 1906. Bull. 1, N. Z. Geol. Survey; 1907, ibid., 3. 

Benson, 1910. Journ. Proc. Roy. Soc. N. 8. W. 

1913: Proc: lann. Soc.’ N.- S.. W., pp: 662-724; 1917, ibid.,. pp- 

223-283. 

Bischof, 1854-5. Chemische Geologie (translated). 

Bodmer-Beder, 1903. N. Jahrb. Min., Beil.-Bd. 16. 

Bonney, 1877. Quart. Journ. Geol. Soc., 33, p. 884; Geol. Mag., p. 59. 

1878. Quart. Journ. Geol. Soc., pp. 769-784. 

— 1879. Geol. Mag., pp. 1-16; 1887, ibid., pp. 1-5; 1889, ibid., p. 431. 

— 1905. Quart. Journ. Geol. Soc., pp. 690-714 (with Miss Raisin); - 

1908, pp. 152-170. 

1914. The crystalline Rocks of the Lizard, Cambridge. 

*Breithaupt, 1831. Schweigger-Seidel Jahrbuch, 3, p. 281. 

Card, 1900. Petrological Notes in Power’s article ‘‘Mineral Resources 
of New Caledonia,’’ Proc. Inst. Mining and Metallurgy, 8, pp. 32-34. 
See also the bibliography of geology of New Caledonia by Dun, ibid., 
pp. 39-44. 

Clarke, 1916. Data of Geochemistry. U.S. Geol. Surv., Bull. 616. 

Clarke and Farquharson, 1916. Geol. Surv., Western Australia, Bull. 68. 

Cornu, 1909. Zs. Chem. Industr. Kolloid, 4, pp. 291-295. 

Crosby, 1894. Journ. Geol. 22, pp. 582-593. 

Damour, 1862. Bull. Soc. Geol. France, 19, p. 413. 

David, 1907. Memoirs, Geol. Survey New South Wales. 

Daubrée, 1879. Etudes synth. Géologie Experimentale, p. 548. 

Delkeskamp, 1907. Zs. prakt. Geol., pp. 393-437. 

Des Cloiseaux, 1896. Bull. Soc. Min. France, 19, p. 48. 

Dieulafait, 1881. Comptes Rendus, 91, p. 1000. 

*Diller, 1910. Journ. Canadian Mining Institute. 

Drasche, 1871. Min. petr. Mitth., p. 1. 

Dresser, 1913. Geol. Survey Canada, Mem. 22, pp. 61-70. 

Dupare et Hornung, 1904. Comptes Rendus, 139, p. 223. 


730 W. N. Benson—Origin of Serpentine. 


Dupare and Siggs, 1913. Bull. Soc. Min. Franee, p. 14. 

Finlayson, 1909. Quart. Journ. Geol. Soc., 65, pp. 351-381. 

Flett and. Hill, 1912. Memoir, Geol. Surv. England and Wales, Sheet No. 
359. 

Gagel, 1910. Centralbl. Min., p. 276. 

Glasser, 1903-4. Annales des Mines, Mémoires. 

Graham, 1917. Economic Geology, pp. 154-202. 

Granagg, 1906. Jahrb. Geol. Reichsanstalt, pp. 367-404. 

Grubenmann, 1910. Die krystallinen Schiefer, 2d edition. 

Harker, 1897. Min. Mag., p. 117 (review of Weinschenk, 1894). 

1904. Mem. Geol. Surv. United Kingdom, pp. 33-4, 46, 112. 

1909. The Natural History of Igneous Rocks. 

Henderson, 1898. Petrograph. geol. Investigations of South African Rocks. 
London (Dulau and Co.). 

*Hochstetter, 1864. Zs. deutsch. geol. Ges., 16, pp. 341-344. 

Holland, 1899a. Geol. Mag., pp. 30-31, 540-547. 

1899b. Memoirs Geol. Survey of India, pp. 133-137. 

Hunt, 1883. Trans. Roy. Soc. Canada. 

Hussak, 1883. Min. petr. Mitth. 5, p. 62. 

*TIssel, 1879. Boll. Com. Geol. Ital. 10, pp. 572-583. 

1889. Tbid., 11, pp. 183-192. 

Jervis, 1860. Quart. Journ. Geol. Soc., 16, pp. 480-486. 

Julien, 1914. Annals New York Acad. Science, 24, pp. 23-38. 

Kalkowsky, 1906. Zs. deutsch. geol. Ges., pp. 1-74. 

Katzer, 1903. Trans. Congrés Geol. Internat. Vienna, pp. 331-346. 

Kispatic, 1890. Wiss. Mitth. aus Bosnien und der Herzogovinien., 7, pp. 
377-484. (N. Jahrb. Min., 1902, 1, p. 67.) 

*Kjerulf, 1864. Verhandl. Wiss. Ges. Christiania. 

Knopf, 1906. Bull. Dept. Geol., Univ. Calif., 4, pp. 425-443. 

*Krotov, 1910. Sitzber. Nat. Ges. Univ. Kasan, Bull. 260,28 pp. (Abstract 
N. Jahrb. Min. 1912, 1, p. 405.) 

Lacroix, 1890. Bull. Carte Geol. France No. 2; 1894-5, ibid., 6, No. 42. 

1897. Comptes Rendus, 124, p. 513. 

1900. Comptes Rendus, 8 Congrés Geol. Internat. 

1903. Mineralogie de la France et ses Colonies, 4. 

1911. Comptes Rendus, pp. 816-822. 

1914. Bull. Soe. Min. France, p. 75. 

Leitmeier, 1913. Article on Serpentine, etc., in Doelter’s Handpuahe der 
Mineralchemie, 2, pp. 385-434. 

Lindgren, 1895. U.S. Geol. Surv., Ann. Report, p. 92. 

Liesegang, 1913. Geologische Diffusionen, pp. 134-145. 

Longchambon, 1910-11. Bull. Carte Geol. France, 21. 

*Lotti, 1899. Mem. Geol. Soc. Belge, 3; also papers, cited by Leck, 
Nature of Ore Deposits (Weed’s translation), 1905, pp. 45-48. 

Low, 1906. Report Geol. Survey Canada. 

McMahon, 1890. Proc. Geol. Assoc. 

*McPherson, 1875. Ann. Soc. Espan. Hist. Nat. 

Marshall, 1904. Trans. N. Z. Inst., 37, pp. 481-484. 

*Mazzuoli e Issel, 1881. Boll. Com. Geol. Ital., 12, p. 313. 

Mennell, 1910. Quart. Journ. Geol. Soc. pp. 355-375. 

1913. A Manual of Petrology. 

Merrill, 1888. Proc. U. S. Nat. Mus., 2, p. 105. 

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*Miuller, 1877. Tschermak’s Min. petr. Mitth., p. 25. 

Murgoci, 1900. Bull. de Sciimte, Bukarest, 9. 

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Palache, 1907. This Journ., pp. 491-495. 

*Pantanelli, 1880. Mem. Accad. Lincei. Ser. 3. (Geol. Mag., pp. 317, 
564.) 


W. N. Benson—Origin of Serpentine. 731 


Peach and Horne, 1899. Memoirs, Geol. Survey of Great Britain. 

*Pellati, 1883. Comptes Rendus, Congrés Geol. Internat. 

Pratt and Lewis, 1905. Geol. Survey of North Carolina, Memoir No. 1. 

Preiswerk, 1901. Inaug. Diss. Basel. 

1903. Verh. Nat. Ges. Basel, 15, pp. 293-316. 

Raisin, 1897. Quart. Journ. Geol. Soc., 53, pp. 246-316. 

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Rinne, 1892. Jahrbuch geol. Landesanstalt, p. 56; 1901, ibid., p. 24. 

*Rose, 1851. Zs. deutsch. Geol. Ges., 3, p. 10. 

Rosenbusch, 1907. Mikr. Physiographie der mass. Gesteine, 1. 

1910. Elemente der Gesteinslehre. 

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1893. Allgemeine und Chemischen Geologie, p. 422. 

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*Schrauf, 1882. Zs. Kryst. 6, p. 336. 

Schuchert, 1910. Bull. Geol. Soc. Amer., 20. 

*Schweizer, 1840. Poggendorff’s Annalen, p. 595. 

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Steinmann, 1905. Ber. Naturf. Ges. Freiburg i. Br., 16, pp. 59-60. 

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1884. Trans. Accad. Lincei, 7. (Cited by Weinschenk, 1891.) 

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Zirkel, 1893. Lehrbuch der Petrographie. 2, pp. 377-401. 


The University of Otago, 
Dunedin, New Zealand. 


732 C. O. Dunbar—Stratigraphy and Correlation 


Arr. XXXVII.—Stratigraphy and Correlation of the 
Devonian of Western Tennessee; by Cart O. Dunsar. 


INTRODUCTION. 


For more than half a century the Devonian of western 
Tennessee has offered one of the most inviting fields to 
the stratigrapher and paleontologist, yet the list of pub- 
lications relating to it comprises little more than a score 
of pages. It remains to-day the last important area of 
Lower Devonian in America to be adequately described. 
These strata are not only replete with finely preserved 
fossils, but they form the most complete and complex 
Lower Devonian sequence in the Mississippi Valley 
province, and the previously unsuspected occurrence here 
of the typical upper Oriskany gives to the Tennessee area 
the highest interest. 

Previous studies——The presence of the Helderbergian 
rocks in Tennessee was first noted by Safford in 1855, 
and in 1869 he more fully described these beds, to which 
in 1876 he and Killebrew applied the name Linden. In 
1899 a second Devonian formation, the Camden chert, 
was made known by Safford and Schuchert, who assigned 
it to the lower Oriskany. Foerste in 1901 defined the 
Pegram limestone, and in his valuable paper on ‘‘The 
Silurian and Devonian Limestones of Western Ten- 
nessee’’ (1903) he more fully described the Camden and 
the Linden formations and subdivided the latter into two 
members, the Ross and Pyburn limestones respectively. 

Scope of the present paper.—This paper is an abstract 
of a report on the Devonian of Tennessee which will be 
published at a later date as a bulletin of the Tennessee 
State Geological Survey. In the complete report the 
stratigraphic relations and faunal characteristics of each 
of the Devonian formations will be described in full, and 
detailed geologic sections of the important exposures will 
be given. The limits of the present paper will permit 
only a brief description of these formations and a 
presentation of the essential conclusions reached. The 
new species appearing in the faunas will be described 
elsewhere at an early date, and the manuscript names are 
therefore used in this article. 


*Published by permission of the Tennessee State Geological Survey. 


of the Devonian of Western Tennessee. 733 


Acknowledgments.—The present study was begun in 
1916, when the writer spent two months in the field, mak- 
ing a large collection of fossils and gathering data which 
formed the basis of a monograph presented in 1917 as a 
dissertation for the degree of doctor of philosophy at 
Yale University. The problem proved so fruitful of 
results that, thanks to the interest of the late Doctor 
A. H. Purdue of the Tennessee State Geological Survey, 
the writer was enabled to spend two additional months in 
the field during the summer of 1917, and to elaborate the 
original study into a completed report. 

The original investigation was made possible by the 
kindness of Professor Charles Schuchert of Yale Univer- 
sity, and the preparation of the manuscript has been done 
in the laboratories of the Peabody Museum under his 
constant supervision. It is a pleasant duty to acknow- 
ledge the writer’s indebtedness to Professor Schuchert 
for many helpful suggestions and criticisms. Thanks 
are also due Doctor Bruce Wade for valuable informa- 
tion given in the field, and for several collections of 
fossils. 

Location.—The Devonian rocks of Tennessee are 
exposed in numerous small irregular areas In a narrow 
belt along the western valley of the Tennessee River. 
They are best developed in Benton, Decatur, Perry, and 
Hardin counties. With very minor exceptions, this 
narrow belt across the state embraces all the Devonian 
strata save the widespread Chattanooga shale. (See 
map, fig. 1.) 


STRATIGRAPHY AND CoRRELATION 


Introduction.—The Devonian rocks in Tennessee suc- 
ceed those of the Middle Silurian, the contact being a 
disconformable one, usually with little physical evidence 
to direct attention to the long interval which separates 
these two series. In most of the exposed sections the 
Lower Devonian rests on the massive Decatur limestone, 
but m the more eastern occurrences it overlaps younger 
Silurian formations. Safford long ago recognized that 
these Lower Devonian strata form a westward-thickening 
wedge separating the Silurian limestones from the suc- 
ceeding but much younger Mississippian shales and 
chert, and that they pinch out and disappear within a few 
miles east of the Tennessee River. 


734. C. O. Dunbar—Stratigraphy and Correlation 


Hires ole 


hZ 


TY 


| = J Mississippian 
— [2:2] €|Chatianooga 


meme ©) Camden 
NG =| Harriman 
fee o Uecaturville 


Zz. 
Zee SS$ Ordovician 


1 Sm 


: 


-~I 
(SU) 
Or 


of the Devoman of Western Tennessee. 


The total thickness of the Devonian strata in Tenn- 
essee is not over 500 feet and the longest single exposed 
sequence is less than 200 feet thick. Nevertheless the 
strata may be divided into nine formations, each sepa- 
rated by longer or shorter intervals of erosion when 


Generalized Devontan Section of Western Tennessee 


Thick- 


= Chautau- Chattanooga shale eon Black fissile carbonaceaus shale 
= quan Hardin sandstone member Thin basal sandstone 
5 
ao] 
= 
Erian 
e 
cs 
7 
6 
3 Fae ti estes io Pesgram limestone jars | Heavy-bedded white limestone 
° can Break 
2 = O- Thin-bedded buff colored 
Camden chert 200'* novaculite 
Break — 
Heavier bedded white and buff 
Harriman chert novaculite 
eran Een? : Heavy-bedded cherty gray 
ian Quall limestone 10"* linestone 
Fr 
= Decaturville chert Porous gray chert 
S —— Break 
= luish shaly limestone and 
4 Birdsong shale Beason tety oo 
I shale 
e& Break 


Flat Gap Massive pure limestone 
Massive limestone and oolitic 
hematite in north - impure 
cherty limestone in south 

Impure thin-bedded cherty 


limestone 


Bear Branch-?yburn 


Ross 


Olive Hill forn. 


Break 
Bluish green calcareous 


i} 
Caen shale 


Rockhouse shale 


— 


some of them were reduced to remnants before the 
deposition of the suceeding formation. In consequence, 
the thicknesses of the several formations, and even the 
sequence, vary from section to section. In spite of this 
fact, the Devonian strata, like those of the Silurian 
beneath, are so generally horizontal in western Ten- 


736 C. O. Dunbar—Stratigraphy and Correlation 


nessee that disconformities are the rule and uneconformi- 
ties the exception, even where the break in sequence is 
known to be a long one. 


LoweER DEVONIAN SERIES 


Innden or Helderbergian Group 


Rockhouse shale.-—Heretofore the Ross limestone has 
been regarded as the lowest member of the Linden, and 
its base as the beginning of the Devonian sequence in 
Tennessee. But in southern Hardin County a still lower 
undescribed formation of fossiliferous shale comes in like 
a wedge between the Ross and the Decatur (Silurian) 
limestone. This formation thickens to the southward, 
where it goes permanently below drainage. A maximum 
thickness of 26 feet may be seen at Rockhouse, a hunters’ 
clubhouse on Horse Creek, 5 miles northwest of Lowry- 
ville, and because of this good exposure the formation 
will be named the Rockhouse shale. It is much thinner 
where it forms a glade near the sulphur spring on Horse 
Creek, 5 miles southeast of Savannah, and it does not 
appear in the sections farther north. It is a glade-form- 
ing, caleareous shale of greenish gray color, interbedded 
with occasional thin bands of light gray crystalline 
limestone which toward the base of the shale become 
thicker and closer set, so that the formation appears to 
grade into the underlying Decatur limestone. 

The shale is replete with fossils, among which the 
bulbous erinoid root Camarocrinus is most conspicuous. 
The fauna consists of thirty-five species, of which one 
third are new. The assemblage is an extremely interest- 
ing one, with a mingling of holdovers from the Silurian, 
along with heralders of early Devonian time. It indi- 
cates for the formation a position very early in the Devo- 
nian and near the Siluro-Devonian boundary line, ‘The 
interesting biota includes Edriocrinus pociliformis, E. 
adnascens n. sp., Camarocrinus, Scyphocrmmus sp., Pleu- 
rodictyum trifoliatum n. sp. (ancestral to: lenticulare 
but mature at the three-celled stage), Dalmanella macra 

n. sp., D. rockhousensis n. sp., Rhipidomella oblata, R. 
preoblata, R. saffordi, Bilobites (small form like bilobus), 
Leptensca adnascens, Dictyonella subgibbosa un. sp., 
Eatonia fissicosta n. sp., Delthyris cyrtinoides n. sp., 
(very near perlamellosa), Nucleospira concentrica, Mer- 


of the Devoman of Western Tennessee. 731 


usta tennesseensis, Meristina roemert, Phacops sp., and 
Six species of gastropods. 

The presence here of Dictyonella subgibbosa nu. sp., 
Nucleospira concentrica, and Merista tennesseensis at 
first inclined the writer to refer this formation to the 
Silurian. On the other hand, the preponderance of the 
fauna is distinctly Devonian and the general paleogeo- 
eraphic conditions likewise strongly support this refer- 
ence. The Upper Silurian in America was a time of 


‘marked restriction of the seas, scarcely a normal marine 


fauna being known anywhere of Upper Silurian time. 
Furthermore, no deposits whatever of this age have yet 
been found anywhere in the whole Mississippi basin. 
The Rockhouse fauna, however, 1s a normal marine 
assemblage, and is present in both Tennessee and Okla- 
homa. It represents, therefore, a wide embayment in 
this region, which is known to have been an early Devo- 
nian basin. The preserval of so thin and soft a forma- 
tion in both Tennessee and Oklahoma beneath Helder- 
bergian strata further supports the belief that it was not 
subjected to long erosion before the deposition of the 
latter. 

The Devonian age of the fauna is indicated by the 
deployment of the gastropods, which make up one fourth 
of its number, for while gastropods are commonly abun- 
dant in the Lower Devonian, the New Scotland having 
thirteen and the Oriskany over twenty species, on the 
other hand but two or three species are found together 
in any Silurian fauna. Likewise the abundance and 
variety of orthoid brachiopods is a Devonian characteris- 
tic. Neither Pleurodictyum nor Edriocrinus is known in 
the Silurian, and the two species of the latter both charac- 
terize the succeeding Linden formations. Large speci- 
mens of Rhipidomella oblata, like those of this formation, 
are never seen in the Silurian, and the Delthyris is closely 
related to perlamellosa, which is so typical of the Helder- 
bergian, and is much larger and more coarsely lamellose 
than-any Silurian species of this genus. 

Although this is the first known occurrence of a Dicty- 
onella in the Devonian in America. Barrande described a 
species long ago from the Middle Devonian (stage G) of 
Bohemia. The presence of the Silurian holdovers, 
Bilobites bilobus, Nucleospira concentrica, and Merista 
tennesseensis, however, as well as the primitive expres- 


738 C. O. Dunbar—Stratigraphy and Correlation 


sion of the Pleurodictyum, which is mature in the three- 
celled stage, indicate for the formation a place very early 
in the Devonian. ‘This inference is further supported by 
the thick development of overlying strata of Coeymans 
and New Scotland age. The Rockhouse shale is, there- 
fore, believed to represent a part of the Keyser formation 
at the known base of the Lower Devonian, although it 
belongs to a different basin and hence shows but slight 
faunal relation to the Keyser. 

Olive Hull formation.—The Olive Hill formation suc- 
ceeds the Rockhouse shale and further northward over- 
hes the Decatur limestone, but, like the preceding forma- 
tion, it is confined to the southern part of the state. The 
present outcrops occur in Hardin County, Tennessee, and 
adjacent portions of Mississippi and Alabama. At about 
the northern edge of Hardin County, it has been rapidly 
bevelled off by interformation erosion, while to the south- 
ward it goes permanently below drainage, with unreduced 
thickness. Lithologically it is a complex formation. 
The best exposure and the one from which it takes its 
name is clearly shown in the bluff on Indian Creek at 
Olive Hill, where it is fully 150 feet thick and consists of 
three distinct lithologic units. These are, in descending 
order, the Flat Gap, the Bear Branch, and the Ross lime- 
stone members. 

The Flat Gap member is a heavy-bedded, coarsely 
erystalline or granular limestone of white or pinkish © 
color, and is very sparingly fossiliferous. Toward the 
top Rhipidomella oblata and Spirifer cycloptera are com- 
mon, and Delthyris perlamellosa and Dalmamites pleu- 
roptyx are quite rare. Colonies of massive bryozoa and 
large pieces of crinoid stems complete the fauna. 

The Bear Branch member consists of more impure, 
coarse-grained limestone in which there is a considerable 
quantity of oolitic hematite. The latter varies greatly 
in richness, and may be disseminated through the lime- 
stone, giving the whole a deep reddish color, or may be 
concentrated into richer bands of ore separated by layers 
of limestone. The member takes its name from an 
exposure on Bear Branch about 2 miles southeast of Olive 
Hill, where it forms a low bluff showing a thickness of 20 
feet of low-grade ore (protore), analyzing on an average 
from 20 to 25 per cent Fe and much resembling the Clin- 
ton iron-ore. So far as the writer is aware, this is the 


of the Devoman of Western Tennessee. 739 


largest deposit of an oolitic iron-ore to be found above 
the Clinton. These beds yielded the ore which was mined 
before the Civil War at a locality about 2 miles southwest 
of Clifton. The cross-bedding which characterizes this 
member bears evidence that the oolite was deposited in 
shallow water. Fossils occur throughout it and are 
especially common in a band of muddy, cherty limestone 
near the middle. The fauna, however, closely resembles 
that of the Ross member below, fifteen of its eighteen 
species being common to the latter. The chief differ- 
ences to be noted are the presence here of Hatoma 
eminens and the absence of Camarocrinus and the 
Scyphoerini which characterize the lower member. 

The Ross limestone member was first described by 
Foerste (1903). It is a dense, fine-grained, siliceous or 
cherty limestone of dark gray color, disposed in thin 
layers from 2 to 5 inches thick. Although very hard and 
compact when fresh, it weathers to a soft, porous, shaly 
sandstone of rusty brown color. Its most characteristic 
fossils are the Camarocrini and Scyphocrimus pyburnen- 
sis and S. prattent. Because of the abundance of the 
erinoid bulbs Foerste called it the ‘‘Camarocrinus or 
Ross limestone.’’ Other fossils occur in more or less 
abundance, the more important of which are lsted 
beyond (page 741). 

For a distance of 20 or 25 miles to the south and south- 
west of Olive Hill, only the lower or Ross limestone mem- 
ber has escaped later erosion, but at Pyburns Bluff on the 
Tennessee River, and at a bluff on Dry Creek near the 
southern line of the state, thick sections of the Olive Hill 
formation are again exposed. Here, however, the sub- 
divisions seen at Olive Hill cannot be clearly recognized. 
Tn the section at Pyburns the formation is between 80 and 
100 feet thick, and its base is below drainage. Here it 
consists of dense, fine-grained, impure and cherty lme- 
stone throughout. The lower portion is characterized by 
Camarocrini, but this fossil is absent in the upper por- 
tion. On this faunal basis Foerste subdivided the sec- 
tion into the Ross limestone below and the Pyburn 
limestone above. The Ross here agrees in faunal and 
physical characters with that at Olive Hill and with the 
intervening sections as well. The Pyburn holds, more or 
less, the stratigraphic position of the Bear Branch mem- . 
ber at Olive Hill, though its lithologic characters are 


740 C. O. Dunbar—Stratigraphy and Correlation 


entirely different. Faunally, however, it seems to agree 
with the latter, especially in the absence of the Camaro- 
erin. It therefore seems highly probable that the 
Pyburn limestone is the equivalent of more or less of the 
Bear Branch; and that the latter is a local shallow-water 
phase is shown by its cross-bedding and the development 
of oolite. The author therefore holds that if the Bear 
Branch member could be traced southward it would be 
seen to grade into the impure gray limestone of the 
Pyburn. In this section the Pyburn member is uncon- 
formably succeeded by Mississippian shales, but in the 
next section to the south, on Dry Creek, the top of the 
Pyburn member becomes more sandy and somewhat 
irregularly bedded, and here it is separated by a shght 
erosional unconformity from a massive, coarsely erys- 
talline, white lmestone which seems to represent the 
Flat Gap member. 

The Ross member only is exposed along Horse Creek 
on the Ross farm 5 miles southeast of Savannah and 
again for 2 or 3 miles above Rockhouse. This same mem- 
ber is exposed in the bluffs along the Tennessee River 
below Cerro Gordo, more extensively at Grandview, and 
also outcrops along tributaries of Indian Creek 3 or 4 
miles east of Cerro Gordo. 

At Olive Hill, where the three members are present, the 
total thickness is over 150 feet; the Ross and a part of 
the Bear Branch members are present near Clifton, but 
only a part of the Ross at Grandview; in the vicinity of 
Saltillo the whole formation is missing, the younger and 
southwardly overlapping Birdsong formation with its 
Eospirifer macropleura fauna here resting directly on 
the Decatur limestone. The progressive thinning of the 
Olive Hill formation toward the north and west, by the 
disappearance of the higher members first, strongly indi- 
cates a considerable interval of erosion following the 
deposition of this formation and preceding the Birdsong 
shale. So thick a series of limestones, with the upper 50 
feet, especially, pure and heavy-bedded, must in all prob- 
ability have extended farther north than the 12 or 16 
miles which separates Olive Hill from Grandview and 
Saltillo. 

The fauna of the Olive Hill formation is chiefly devel- 
oped in the Ross member, from which fifteen species pass 
upward into the Bear Branch and four continue into the 


of the Devoman of Western Tennessee. rest 


terminal Flat Gap member. The more important forms 
of the Ross limestone are: Pleurodictyum lenticulare, 
Favosites comcus, Edriocrinus pocilliformis, Scyphocri- 
nus pratten, S. pyburnensis, and S. mutabilis (with their 
corresponding Camarocrini), Rhipidomella oblata, Lep- 
tostroplia becku, Stropheodonta planulata, Anastrophia 
vernewuli, Rensselerima medio plicata, Delthyris perlamel- 
losa, D. octocostata mut. tennesseensis, Meristella atoka, 
M. levis, Phacops logam and Dalmamntes pleuroptys. 
The Bear Branch member contains, in addition, Hatonia 
eminens, but it and the Flat Gap member lack many 
species which occur in the Ross, especially the Scypho- 
erini and Camarocrinus. 

Of this fauna of fifty-eight species, fifteen are indig- 
enous to Tennessee, while twenty elsewhere occur in 
both the Coeymans and New Scotland, twenty-one being 
elsewhere confined to the New Scotland and one to the 
Coeymans. Its relations are therefore with the higher 
Coeymans and lower New Scotland, but it has more 
decidedly the impress of the latter. It does not, however, 
contain a number of significant species such as Dalman- 
ella perelegans, D. eminens, Orthostrophia strophomen- 
oides, Camarotechia bialveata, and especially Eospirifer 
macropleura, which are very distinctive of the New 
Scotland, and which do occur in the succeeding Birdsong 
shale. The latter formation is the more exact equiva- 
lent of the typical New Scotland, and since, therefore, the 
Olive Hill formation is considerably older, as shown by 
the interval of erosion which separates these formations, 
the Olive Hill must be referred to very early New Scot- 
land time, if, in fact, it does not represent a part of the 
higher Coeymans. 

The close relation of this fauna to that of the Birdsong 
shale will be noted below in the discussion of the latter. 

Birdsong formation.—This shaly member of the Lin- 
den is the best known of the early Devonian formations of 
western Tennessee, because of its finely preserved fossils. 
It is the one exposed at Linden and is much better devel- 
oped west of the Tennessee River and from Perryville 
northward to the mouth of Big Sandy River. It was 
provisionally correlated by Foerste (1903) with the 
Pyburn limestone which he defined in the section at 
Pyburns Bluff near the southern edge of the state. If 
this correlation could be substantiated, the name Pyburn 


Am. Jour. Sct.—FourtH Series, Vou. XLVI, No. 276.—DrcremBeER, 1918. 


742, C. O. Dunbar—Stratigraphy and Correlation 


would be a most unfortunate one to apply to the forma- 
tion, since the hmestone at Pyburns is an isolated occur- 
rence about 40 miles south of the nearest good section of 
the formation under discussion. Moreover, it is neither 
faunally nor lithologically typical or representative of 
the latter. Itis the conclusion of the present study, how- 
ever, that the Birdsong formation is distinct from and 
younger than the Pyburn limestone, and it is therefore 
given this new name because of its ‘typical development 
along the valley of Birdsong Creek. 

At the base of the formation is 8 to 10 feet of rather 
thick-bedded, coarsely crystalline, gray limestone, fol- 
lowed by a transition zone of thinner bedded crystalline 
limestone, interbedded with bluish calcareous shale, pass- 
ing into bluish shaly limestone or limy shale which forms 
the upper half or two thirds of its thickness. It weathers 
into bluish clay and a rubble of small lumps of limestone, 
and frequently forms barren hillsides or ‘‘glades.’’ 

The formation attains a thickness of about 45 feet 
along Birdsong Creek, and continues with but little 
change, either lithologically or faunally, through north- 
ern Decatur County and Benton County, though it is 
generally below drainage in central and northern Benton 
County. About 5 miles above the mouth of Big Sandy 
River, where it comes to the surface again, it reveals an 
additional 20 feet of higher shaly layers not to be seen 
further south. To the south and east of Perryville it 
has been beveled off by interformational erosion, but a 
small outlier still persists in the vicinity of Saltillo. A 
thickness of only 8 feet of these strata is exposed at the 
boat landing at this locality. The association here of 
Anastrophia verneut, Dalmanella eminens, and Eospiri- 
fer macropleura (very common) leaves no doubt of their 
reference to the Birdsong formation, and they apparently 
do not represent even the lowest layers, so that the for- 
mation appears to overlap to the south. 

In all of the sections west of the Tennessee River this 
formation rests with a disconformable contact upon the 
Decatur limestone of the Silurian, the boundary line 
between them being usually difficult to locate. Farther 
northeastward, at Beardstown on Buffalo River and near 
Cumberland City in the Wells Creek basin, it overlaps 
younger Silurian strata. 

Excepting the limestone at its base, the Birdsong for- 


of the Devoman of Western Tennessee. 743 


mation is extremely fossiliferous, and the perfect preser- 
vation of its fossils is scarcely to be duplicated in the 
whole of the Lower Devonian. Brachiopods greatly 
predominate, except in a narrow zone at the top of the 
formation in Benton and Decatur counties which is 
extremely crowded with bryozoa. Some of the more 
important fossils are: Plewrodictyum lenticulare, Favo- 
sites conicus, F’. foerster n. sp., Edriocrinus pocilliformis, 
Orthostrophia strophomenoides, Dalmanella subcarinata, 
D. perelegans, D. eminens, Rlupidomella oblata, R. emar- 
gmata, Bilobites varicus, Leptostrophia becku, Lepte- 
msca adnascens, L. concava, Anastropha verneuili, 
Gypidula multicostata n. sp., Hatoma tennesseensis 
n. sp., Camarotechia bialveata, Rensselerina medioplh- 
cata, EHospirifer macropleura, Delthyris perlamellosa, 
Spirifer cycloptera, Trematospira sumplex, T. costata, 
Meristella arcuata, M. atoka, M. levis, Phacops logam, P. 
hudsomca, Dalmantes pleuroptyx, and D. retusus n. sp. 
The very striking resemblance of this fauna to that of 
the New Scotland of New York has long been recognized. 
Of the ninety-nine species identified from this forma- 
tion, sixty also occur in the New Scotland, and among 
these are almost all the diagnostic species of the latter, 
especially noteworthy being Hospirifer macropleura. 
Considering the great distance which separates Tennes- 
see, and even Maryland, from New York, the correspond- 
ence in these faunas is unusual and clearly indicates not 
only an equivalence in age, but the establishment of a 
rather direct communicating seaway. On the other hand, 
there are certain elements in the Birdsong fauna which 
do not recur at this time in the Appalachian trough and 


which appear to have reached Tennessee through the 


previously established southern embayment. Such, for 
example, are the various species of Scyphocrinus with 
their associated Camarocrini, the genus Rensselerina, 
characteristic new species of Hatonia and Gypidula, and 
Meristella atoka. The Scyphocrini were sequestered 
somewhere in the southern waters, their bulbs appearing 
in great abundance in both Oklahoma and Tennessee, 
and ranging from the Decatur limestone of the Middle 
Silurian to the top of the Birdsong shale, whereas they 
only temporarily invaded the Appalachian trough, 
appearing in a zone near the middle of the Keyser in 
Maryland and in the Manlius? of New York. 


744 C. O. Dunbar—Stratigraphy and Correlation 


The intimate relationship of this fauna to that of the 
Ross member of the Olive Hill formation is shown in 
the fact that fifty-one out of fifty-eight species from the 
latter pass into the Birdsong shale. On the contrary, 
there is great deployment of Camarocrinus in the Ross. 
as in the Rockhouse shale, whereas these fossils are gen- 
erally not common in the Birdsong formation, and nei- 
ther the distinctive Scyphocrinus prattent nor its huge 
bulb has been seen in the latter formation. At the same 
time, thirty-five species appear in the Birdsong that have 
not been found in the Ross. The most importance is 
attached to Hospirifer macropleura, which is always to 
be found in the Birdsong and never in the Olive Hill. 
Equally characteristic species of the former formation, 
such as Hatona tennesseensis, Camarotechia bialveata, 
Dalmanella perelegans, and Dalmanites retusus, are 
also lacking in the Olive Hill. The absence of these 
species from the Ross and Pyburn limestones may not be 
attributed to the control of the sediments, since they are 
known to occur elsewhere in impure cherty limestones. 
To this fauna evidence for the distinctness of the Bird- 
song shale from the Olive Hill formation should be added 
that of the general field relations. To correlate the Bird- 
song shale with the Ross limestone would demand a very 
abrupt faunal and lithologic change between Perryville 
and Grandview, though each formation maintains its own 
characters with uniformity for many miles from these 
localities. But the existence of any such transition is 
negated by the outlier of the Birdsong formation at Sal- 
tillo, which is as far south as Grandview. This being 
true, the erosion of the Ross limestone from the vicinity 
of Saltillo must have preceded the deposition of the 
Birdsong shale, and this fact, as well as the faunal evi- 
dence, precluded the correlation of the latter with either 
of the members of the Olive Hill formation. 

Decaturville chert—This thin formation is the highest 
member of the Linden group and unconformably overlies 
all of the preceding formations. It is well developed in 
the vicinity of Decaturville, from which place it takes its 
name. The most distinctive and widespread part of the 
formation is a very porous and extremely fossilferous 
gray or slate-colored chert, which on the surface is 
stained with iron rust, and which forms a heavy layer 
from a few inches to over a foot thick. Beneath this is 


| 
| 
| 


of the Devonian of Western Tennessee. 745 


thinner bedded sandy chert which weathers more readily 
and is not well exposed. This lower portion seems to 
vary in thickness from place to place, but was not seen to 
exceed 5 feet. Although so thin, this formation, with 
both its distinctive lithology and fauna, extends over half- 
way across the state. It was not seen north of Camden, 
but in various exposures along Birdsong Creek and fur- 
ther south on Lick Creek it disconformably succeeds typ- 
ical sections of the Birdsong shale. Where best devel- 
oped about the town of Decaturville, it rests on the basal 
layers of the Birdsong formation, though a full section 
of the latter is preserved at Perryville only 6 miles to 
the northeast. In the vicinity of Saltillo it rests in 
places on remnants of this formation, and elsewhere on 
the Decatur limestone, while 5 or 6 miles to the east at 
Grandview it sueceeds the Ross limestone and near Wal- 
nut Grove at the south edge of the state it overlies the 
Olive Hill formation. Thus far it has not been identified 
east of the Tennessee River except in Hardin County. 

The chert is replete with fossils which are preserved 
both as natural molds and casts and as replacements of 
the shell in white silica. The most striking feature of 
the fauna is the large size of many species, which exceeds 
their norm by 25 to 50 per cent. Some of the important 
fossils are as follows: Favosites comcus, Pleurodict- 
yum lenticulare, Dalmanella planoconvexa, Rhipidomelila 
oblata, Leptostropma becku, Leptenisca concava, Schu- 
chertella woolworthana, Chonostrophia jervensis, Eato- 
ma singularis, E. medialis, Delthyris perlamellosa, 
Meristella cf. levis, Anoplotheca concava, Homalonotus 
sp. (large), and Phacops hudsomica. 

This fauna is closely allied to those of the Birdsong 
and New Scotland formations and there are affinities 
which equally relate it to the Becraft. Of its nineteen 
species, twelve occur in both the New Scotland and 
Becraft, and two others have closely related species in 
both. Of-the remaining forms, Leptenisca concava and 
Phacops hudsonica are elsewhere confined to the New 
Seotland, while Chonostrophia jervensis is limited to the 
Becraft. The chief distinction separating this fauna 
from that of the Birdsong or New Scotland is the absence 
here of many characteristic species of these formations, 
such as Hospirifer macropleura, Bilobites varicus, and 
Anastrophia verneuilt. On the other hand, it lacks some 


746 C. O. Dunbar—Stratigraphy and Correlation 


of the most distinctive forms of the Becraft, such as 
Aspidocrinus scutelforms, Rhipidomella assimilis, and 
Spirifer concunnus. The faunal evidence is, therefore, 
not very conclusive, but it is not out of harmony with the 
assignment of this formation to early Becraft time. 
This reference of the formation, however, is based rather 
on its stratigraphic position. The distinct unconformity 
with which the formation overlaps the Birdsong shale 
indicates a considerable time break between it and the 
New Scotland equivalent, and since a thick section of the 
latter is already represented in the Birdsong formation, 
the distinctly younger Decaturville chert seems to be 
best referred to the earliest Becraft. The Becraft sea 
probably entered the Mississippi basin by the same route 
as that of the New Scotland, since it is present in south- 
ern Illinois, where Savage (1908) has reported such char- 
acteristic Becraft fossils in the upper part of the Bailey 
limestone as Aspidocrinus scutelliformis and Spurifer 
concinnus, associated with Oriskama condom (?) and O. 
sinuata Nn. var. 


Oriskany Group 


The upper Oriskany, with its character ae! fauna of 
large species, is typically developed in the Appalachian 
trough extending from Gaspé to southern Virginia, but 
previous to 1913 it was believed that this sea had never 
attained the Mississippi basin. In that year, however, 
Weller (1914) discovered a very small occurrence of 
white limestone in eastern Missouri carrying this distine- 
tive fauna. It is one of the chief contributions of the 
present study to record an extensive development of the 
typical upper Oriskany along the Tennessee valley, where 
it attains a thickness of over 50 feet and is exposed in 
numerous places for a distance of more than 75 miles. It 
unconformably overlies the Linden group and is in turn 
separated by local unconformities from the succeeding 
Camden chert. The Oriskany equivalents are here 
divided into the lower Quall and the higher Harri- 
man formations. The former name is applied to the 
basal siliceous limestone, and the latter to the much 
thicker and more extensively distributed superimposed 
novaculite. 

Quall limestone—This thin limestone formation is 
confined to the southern part of the state, having a 


of the Devoman of. Western Tennessee. TAT 


maximum thickness of only about 10 feet where exposed 
along Dry Creek, a small tributary which enters the 
Tennessee River near Walnut Grove. It thins out to 
the northward, being locally present in the bluff at 
Grandview, where its greatest thickness is scarcely 4 feet. 
The only other observed outcrop is at the town spring at 
Linden, where it is about 3 feet thick and rests discon- 
formably on the lower part of the Birdsong formation. 
In these three exposures it rests in turn on the Flat Gap 
limestone, the Decaturville chert, and the basal part of 
the Birdsong shale, showing an unconformable relation 
indicative of a considerable break in the sequence, which 
is in harmony with the faunal evidence. 

Where freshly exposed, the limestone is light gray in 
color and rather fine-grained. It is disposed in layers 
from 18 to 20 inches thick and appears to be magnesian 
and highly siliceous. Upon deep weathering, it forms a 
very porous, rotten, white and buff chert with yellow 
elay, in which fossils abound as free pseudomorphs or 
replacements in silica. The occurrence at Linden is more 
impure and darker in color. 

The small fauna which has been secured includes Edrio- 
crus sp., Striatopora sp. (large), Plethorhyncha cf. 
barrandei, Beacha suessana, Spirifer arenosus, S. mur- 
chisom, S. purduet, and Platyceras gebhardi. This fauna 
is clearly related to those of the upper Oriskany of the 
Appalachian trough and to the succeeding Harriman 
novaculite, having no species in common with the Linden 
or Helderbergian. The writer was first inclined to con- 
sider the Quall as only a member of the Harriman, but 
because of the stratigraphic relations described below 
under the latter formation, and because of certain faunal 
differences—though largely negative—it seems best to 
regard it as a distinct formation. 

Harriman novaculite—This formation is named for 
Harriman Creek, in Decatur County. It consists of 
so called chert or novaculite that is nearly white on 
fresh exposure but weathers to shades of yellow and buff. 
It is disposed in layers ranging from a few inches to over 
a foot in thickness, and is very hard and brittle, being 
thoroughly fractured, where weathered, into small angu- 
lar fragments; in this condition it so closely resembles 
the Camden ‘‘chert’’ that only the fossils may be relied 
upon to distinguish these two formations. Where freshly 


748 C. O. Dunbar—Stratigraphy and Correlation 


exposed, it is generally whiter and more heavily bedded 
than the latter. 

The formation extends nearly across the state, attain- 
ing a thickness of 55 feet near the mouth of Big Sandy 
River in the north, and showing an almost equal thickness 
at Cerro Gordo and Grandview in northern Hardin 
County. Itis well developed in the vicinity of Perryville 
and Parsons, where it forms ‘‘chert’’ hills and has been 
largely quarried for road metal. 

In successive outcrops the Harriman novaculite rests 
upon the mid-Silurian and various members of the Lin- 
den group, giving the clearest evidence that it is sepa- 
rated from the latter by a considerable break and interval 
of erosion. Near the mouth of Big Sandy River it lies 
above the highest layers of the Birdsong shale, while on 
Sycamore Creek near Holladay it succeeds a zone 20 
feet lower, and within 2 miles to the east on Wolf Creek 
it rests on the Decatur, all of the Linden being locally 
absent through erosion. Further south at Perryville, it 
rests again on the Birdsong shale, but 6 miles further to 
the southwest at Decaturville, the two formations are 
separated by the Decaturville chert. At Grandview it 
locally succeeds the Quall limestone, though the latter is 
absent at Cerro Gordo, and here it rests en the Ross 
member of the Olive Hill formation. Further southward, » 
where the Quall limestone is better developed, the Har- 
riman formation is absent. 

This novaculite is generally fossiliferous, but unevenly 
so. Near the mouth of Big Sandy River, fossils could 
be found only near the top, but the portion exposed on 
Cypress Creek near Camden is rich in organisms, and 
here was secured the largest fauna. At Perryville the 
middle portion is abundantly fossiliferous, but the upper 
and lower part only sparingly so, while the section at 
Grandview is moderately fossiliferous. The fossils are 
preserved as natural molds and casts similar to those in 
the Camden ‘‘chert.’’ The fauna of twenty-five species 
includes Leptena ingens n. sp. (very large), Leptostro- 
phia magniventra, Anoplia nucleata, Chonostrophia com- 
planata, Plethorhyncha ef. barr andei, Rensseleria ovot- 
des, Oriskana safford n. sp., Spirifer murchisom, S. 
arenosus, S. paucicostatus, Metaplasia pyxidata, Meris- 
tella lata, M. rostellata, Anoplotheca dichotoma, Lepto- 
ceha flabellites, Platyceras gebhardi, ete. 


of the Devoman of Western Tennessee. 749 


The relation of this fauna to that of the upper Oriskany 
in the Appalachian trough is very striking, especially in 
consideration of the great distance of over 600 miles 
which separates these ‘regions. Nineteen of the twenty- 
five species found in Tennessee occur elsewhere in the 
upper Oriskany, thirteen of them being common to both 
Maryland and New York, and these include almost all the 
distinctive Oriskany forms. The distinctness of this 
fauna from that of the Linden group below is shown by 

the fact that only one species, the long-ranging Eatona 
peculiaris, has been found in both. 

The fauna of the Little Saline limestone of Missouri, 
discovered by Weller -(1914), has not yet been described, 
and Weller’s report is awaited with great interest. Nev- 
ertheless a preliminary comparison made by the writer 
with a collection sent to Yale by Professor Weller indi- 
eates that the Missouri fauna is less closely related to 
that of the Harriman novaculite than either of these is 
to that of the Appalachian trough. 


Middle Devonian Series 
Ulsterian Group 


The earlier Middle Devonian or Ulsterian is repre- 
sented in Tennessee by two formations, the Camden chert 
and the Pegram limestone. The former is well devel- 
oped in the northern half of the valley, where it attains a 
measured thickness of 164 feet, while the latter is a very 
thin formation of which only remnants are now exposed 
at three widely separated localities. 

Camden chert.—This formation was named by Safford 
and Schuchert (1899) for the village of Camden, Ten- 
nessee, where it is typically developed and well exposed. 
Although previous workers have regarded it as an Oris- 
kany formation, it is one of the chief conclusions of the 
present study that it forms an early part of the Middle 
Devonian. When first described, it was referred to the 
lower Oriskany, and attention was especially directed to 
the absence here of the large brachiopods which char- 
acterize the upper Oriskany. When in 1907 Savage 
restudied the equivalent of these beds in Illinois, where 
they are known as the Clear Creek chert, he showed that 
they pass apparently by continuous deposition into the 
Grand Tower (Onondaga) formation, there being an 


750 C. O. Dunbar—Stratigraphy and Correlation 


interbedding of the upper layers of the Clear Creek chert 
with the basal layers of the Grand Tower. He also 
clearly showed the intimate relation of the faunas of 
these two formations, and therefore assigned the Clear 
Creek to the highest Oriskany, assuming that deposition 
was continuous in southern Illinois from the Lower into 
the Middle Devonian. At that time, however, the typical 
upper Oriskany was entirely unknown in the Mississippi 
basin and the Camden chert seemed best to occupy this 
interval, the uniqueness of its fauna being ascribed to 
the fact that it belonged to a different basin from that of 
the Appalachian trough. The finding by Weller of typi- 
cal Oriskany in Missouri and especially the discovery of 
its good development in western Tennessee, where it is 
unconformably succeeded by the Camden chert, give a 
new vista to the problem of correlation. 

The Camden chert is a white to yellow brittle novacu- 
lite disposed in thin hard layers, usually from 1 to 3 
inches thick—rarely as much as 8 or 10 inches—which are 
commonly separated by gritty clay along the bedding 

planes where weathering has begun. Locally there are 
- irregular, more or less vertical pockets of white silica, 
apparently the result of leaching along ground-water 
passages. The rock breaks with an irregular fracture 
into angular, sharp-edged fragments, and it is always so 
thoroughly fractured that even the fresh quarry faces 
quickly break down into a talus slope, while natural out- 
crops appear only as a loose rubble of angular pieces of 
buff ‘‘chert’’ or novaculite, mostly smaller than one’s fist. 
So characteristic is this broken-up condition of the rock 
that the quarries where it is extensively worked for bal- 
last or road metal are generally known as ‘‘gravel pits.”’ 
It has proved to be one of the finest of road metals, as it is 
very slightly soluble and has the important quality of 
‘“bonding’’ well so as to form a hard surface under traf- 
fic. The formation displays these physical characters 
in all the known exposures except the one at the ‘‘whirl’’ 
in Buffalo River, 4 miles north of Bakerville. Only the 
upper layers are here exposed and these are directly 
followed by the Pegram limestone. They consist of 
an alternation of layers of yellowish chert, 2 to 9 inches 
thick, and layers of dense bluish gray limestone. The 
fauna of these layers indicates that they are stratigraph- 
ically higher than those elsewhere exposed where the 


of the Devoman of Western Tennessee. 751 


formation is unconformably overlain by the much 
younger Chattanooga shale. 

The Camden chert attains a total exposed thickness of 
164 feet along Cypress Creek southeast of Camden, and 
if the layers exposed at the ‘‘whirl’’ on the Buffalo River 
be added, it has a total of about 200 feet. The log of the 
city well at Camden shows a thickness of 275 feet, which 
is to be divided between this and the Harriman chert. It 
is well developed from Big Sandy northward along the 
course of the Big Sandy River, and it also extends south 
of Camden along the valley of Birdsong Creek, but it 
seems not to extend as far south as Perryville and Par- 
sons, the chert there exposed being referable entirely to 
the Harriman formation. While thicker in the more 
western sections, it appears to thin out by overlap east- 
ward, only the succeeding Pegram limestone reaching as 
far eastward as Nashville, and in most sections its thick- 
ness is greatly reduced by later erosion. The formation 
doubtless continues under cover into southern Illinois, 
where it has a maximum thickness of 237 feet and is 
known as the Clear Creek chert. 

The magnitude of the unconformity which separates 
the Camden chert from the Harriman chert below is 
shown by the circumstance that the latter has a thickness 
of 55 feet on the lower course of Big Sandy River, but is 
entirely absent by erosion on Rushing Creek about 7 miles 
south of Big Sandy, where the Camden chert rests 
directly on the Birdsong shale. Just south of Camden, 
the Harriman chert is again well developed beneath the 
Camden, but here its thickness can not be determined. 
The sharpness of the faunal break still further empha- 
sizes the importance of the hiatus between these forma- 
tions. 

The fossils of the Camden chert are preserved as sharp 
natural molds and casts of both the exterior and interior, 
showing details of sculpture and internal characters in 
unusual perfection. As a whole the formation is abun- 
dantly fossiliferous, but some layers are relatively barren 
while others are replete with fossils. Among the more 
characteristic species of this formation are: Stropheo- 
donta ef. hemispherica, Schuchertella pandora, Eodevo- 
naria arcuata, Chonetes hudsonicus mut. camdenensis 
n. mut., Anoplia nucleata, Chonostrophia reversa, Cen- 
tronella glansfagea, Amplhigema curta, Oriskamia con- 


752, C. O. Dunbar—Stratigraphy and Correlation 


dom, Atrypa reticularis (var. with very large growth 
lamelle), Spirifer duodenarius, S. acuminatus, S. hemi- 
cyclus, S. worthenanus, Reticularia fimbriata, Metaplasia 
pyxidata, Pentagona ‘unisulcata, Leptocehha flabellites, 
Phacops cristata, and Dalmanites myrmecophorus. In 
the higher layers exposed on Buffalo River were found in 
oe Rhipidomella ef. penelope and Spirifer macro- 
thyris 

The relation of this fauna to that of the Clear Creek 
chert of Illinois is very close. Of the forty-two species 
identified from Tennessee, twenty-four occur in Illinois 
and five more have close affinities which will probably 
prove to be identities. Even these numbers, however, 
fail to express the close resemblance of the faunas, for the 
twenty-nine species just noted embrace practically all 
those of frequent occurrence in either fauna. 

In seeking to compare the fauna with those of the 
Oriskany and the Onondaga, about one-fourth of the 
species must be eliminated, because they are indigenous 
and peculiar to this southwestern embayment, so that 
their stratigraphic importance is not known. Seven 
additional species range through both Oriskany and 
Onondaga and may therefore be eliminated from consid- 
eration. Of the remaining nineteen, four are elsewhere 
confined to the Oriskany and twelve to the Onondaga. 
The assemblage here of such characteristic Onondagan 
species as Chonostrophia reversa, Centronella glans- 
fagea, Spirifer duodenarius, S. acwminatus, Pentagonia 
unisulcata, Phacops cristatus, and Dalmanites myrmeco- 
phorus, is of the highest significance, and since this is 
corroborated by the facts that the Camden is separated 
by an interval of erosion from a normal development of 
typical upper Oriskany, which it overlies, and that it 
passes without a break into a recognized Onondaga for- 
mation (the Grand Tower of Illinois), the conclusion 
becomes inevitable that it belongs with the Onondaga in 
the Middle Devonian. 

The distribution of this formation in Tennessee and 
Illinois, and possibly Arkansas (the Arkansas novacu- 
hte), the absence of the formation from the Appalachian 
trough, and finally its faunal affinities with the Middle 
Devonian of South America, already pointed out by Schu- 
chert (1906), all indicate that it represents a southern or 
Gulf embayment. The species which show a close rela- 


of the Devoman of Western Tennessee. 753 


tion to the Maecuru fauna of South America are Stro- 
pheodonta ef. blanviller, Anoplia nucleata, Chonetes hud- 
somicus mut. camdenensis, Amphigema curta, Spirifer 
duodenarius, Leptocelia flabellites, and Actinopteria 
communis. 

Succeeding the Clear Creek in Illinois, the Grand 
Tower (Onondaga) formation is about 150 feet thick. 
The characteristic and widespread coral fauna does not 
appear here until about the middle of the formation. 
Savage’s studies have led to the conclusion that its 
appearance marks the first confluence of this southern 
embayment with the northeastern one whence the corals 
seemingly came. Both the corals and cephalopods, he 
believes, are present in New York in lower strata equiva- 
lent to the lower half of the Grand Tower formation. If 
this be true, the inclusion of the Clear Creek (and Cam- 
den) chert in the Ulsterian series makes a thickness of 
over 300 feet of strata in this southern embayment before 
the advent here of the coral fauna. The incursion of this 
embayment must therefore have taken place very early 
in the Middle Devonian, and the Camden (and Clear 
Creek) chert may be partially at least the equivalent of 
the Esopus and Schoharie grits of New York. 

Pegram limestone.—This thin formation of heavy- 
bedded white limestone was named by Foerste (1901) for 
the village of Pegram, Tennessee. It attains a maximum 
thickness of 12 feet at this locality, but thins out eastward 
to 3 feet near Newsom. Only three widely separated 
remnants of the formation are known, the first being the 
small area about Pegram where several outcrops occur, 
the second fully 50 miles west at the ‘‘whirl’’ on Buffalo 
River 4 miles north of Bakerville, and the third in Wayne 
County near Fortyeight P. O. 

The exposure 3 miles west of Newsom has yielded the 
diagnostic Onondagan blastoid, Nucleocrinus verneualr 
and in addition Stropheodonta demissa, S. perplana, 
Rhipidomella penelope, and Nucleospira concinna. The 
formation at the locality on Buffalo River 4 miles north 
of Bakerville is replete with Onondaga corals, among 
which are Cyathophyllum rugosum, species of Helvo- 
phyllum, Blothrophyllum, Cystiphyllum, Cyathophyllum, 
ete. 

The fauna clearly indicates an equivalence with the 
Jeffersonville limestone of Indiana and Kentucky, of 


754 C. O. Dunbar—Stratigraphy and Correlation 


which the Pegram limestone is supposed to be a south- 
ward extension. 

The writer has not seen the exposure on Mills Creek 
near Fortyeight P. O. in Wayne County, but it is 
described by Drake (1914) as ‘‘nearly 6 feet of pebbly, 
coarsely crystalline, gray limestone.’’ Here it rests on 
the Brownsport group of the Silurian, while farther east 
at Newsom it succeeds the still younger Lego limestone, 
but on Buffalo River it succeeds the Camden chert. At 
this locality only 45 feet of the highest part of the Cam- 
den formation is exposed, but within a few miles west at 
Camden it is known to be at least 164 feet thick. The 
overlap of the Pegram limestone eastward and south- 
eastward over the Silurian indicates that the Camden 
chert thins out rapidly in this direction by overlap, since 
it was closely followed by the Pegram. 

The formation is probably separated by a short inter- | 
val from the Camden chert, since the coral fauna which 
characterizes it does not appear until about the middle 
of the Grand Tower formation in southeastern Illinois, 
the lower part of the latter being unrepresented in 
Tennessee. ea: 


? Upper DEVONIAN SERIES 
? Chautauquan Group 


Chattanooga shale-—The Chattanooga shale is a wide- 
spread formation, extending from the western valley to 
the mountains of eastern Tennessee, and from Alabama 
into Kentucky, overlapping many formations ranging in 
age from Ordovician to Middle Devonian. In central 
Tennessee it attains a considerable thickness, but in the 
western valley it is uniformly thin and is locally absent 
at many places, due apparently to later erosion. Here it 
generally ranges between 2 and 10 feet, and rarely 
exceeds 20 feet. 

The shale proper is a black, fissile, carbonaceous shale 
of fine and even grain, and smells strongly of petroleum 
when struck with a hammer. Crystals and concretions 
of pyrite occur commonly and thin concretionary layers 
of gypsum may be found near the base. 

Beneath the black shale there is usually present a thin 
basal sandstone called the Hardin sandstone member. It 
generally forms a single massive layer of fine-grained 
muddy gray sandstone from a few inches to 3 or 4 feet 


Or 


of the Devomian of Western Tennessee. 75 


thick, but it is absent at many_localities and at Olive Hill 
has the exceptional thickness of 15 or 16 feet. Locally 
the base of the sandstone is conglomeratic. 

Fossils in the Chattanooga shale are very meagre and 
of slight significance in correlation, being limited to sup- 
posed spore cases (Sporangites), microscopic annelid 
and conodont teeth, and a small species of Lingula. 
These fossils are abundant in the base of the shale in the 
well known quarry 3 miles west of Newsom, and they 
have been found at various other localities in western 
Tennessee. The Lingula has often been identified as 
L. spatulata, but the specimens collected by the writer 
are certainly distinct from that species, agreeing much 
more closely with L. melie of the Sunbury shale of 

hio. 

The age of the Chattanooga shale is a mooted question. 
Most workers have regarded it as Upper Devonian, and 
both the Tennessee State Geological Survey and the 
United States Geological Survey continue to do so, while 
on the other hand Ulrich (1912) refers it to the base of 
the Mississippian. The known fauna being of little 
value, the problem will probably be solved only bya broad 
study of the stratigraphic relations of this widespread 
formation. No conclusive evidence could be found by the 
writer in western Tennessee, and he does not wish to take 
a decisive stand, but it has seemed advisable to conform 
to the established usage of the state and national surveys 
in referring the Chattanooga shale to the Upper Devo- 
nian. 


References. 
Drakg, N. T. : 
1914. Economic geology of the Waynesboro Quadrangle, 
Resources of Tenn., 4, No. 3, 99-120. 
Forrsts, A. F. 
1901. Silurian and Devonian limestones of Tennessee and 
Kentucky, Bull. Geol. Soc. America, 12, 395-444. 
1903. Silurian and Devonian limestones of western Ten- 
. nessee, Jour. Geology, 11, 697-715. 
SAFForpD, J. M. 
1855. A geological reconnaissance of Tennessee, first bien- 
nial report. 
1861. The Upper Silurian beds of western Tennessee; and 
Dr. F. Roemer’s monograph, this Journal (2), 31, 
205-209. 
1869. Geology of Tennessee. 


756 C. O. Dunbar—Stratigraphy and Correlation. 


SAFForD, J. M., and KiLLEBREw, J. B. 
1876. The elementary geology of Tennessee. 
SAFFORD, J. M., and ScHucHERT, C. 
1899. Camden chert of Tennessee and its lower Oriskany 
fauna, this Journal (4), 7, 429-431. 
SavacE, T. E. 
1908. Lower Paleozoic stratigraphy of southwestern Illinois, 
Illinois Geol. Survey, Bull. 8, 103-116. 
1910. The Grand Tower (Onondaga) formation of Illinois 
and its relation to the Jeffersonville beds of 
Indiana. Trans. I[llinois State Acad. Sci., 3, 
116-132. 
ScHUCHERT, C. : 
1906. Geology of the lower Amazon region, Jour. Geology, 
14, 722-746. 
Unricu, E. O. 
1912. The Chattanoogan series, with special reference to 
the Ohio shale problem, this Journal (4), 34, 
157-183. 
WAbpBE, B. 
1914. The geology of Perry County and vicinity, Resources 
of Tenn., 4, No. 4, 150-181. 
WELLER, S. 
1914. Western extension of some Paleozoic faunas in south- 
eastern Missouri, Bull. Geol. Soc. America, 25, 
135-136. 


Yale University. 


Richard Rathbun. T57 


RICHARD RATHBUN AND HIS CONTRIBUTIONS 
io ZOOLOGY. 


In the October number of the Journal (page 620) men- 
tion was made of the death of Dr. Richard Rathbun, 
Assistant Secretary of the Smithsonian Institution and 
for nearly twenty years in charge of the United States 
National Museum. 

Dr. Rathbun states in a brief autobiography which has 
kindly been placed in the hands of the writer that his 
interest in science dated from 1868 when, at the age of 
sixteen years, he was attracted by the fossils in the 
quarries near Buffalo, New York, in which he was 
employed as financial clerk and overseer of work. Fasei- 
nated by the glimpses of the ancient life of the world as 
revealed in Hugh Miller’s ‘‘The Old Red Sandstone,”’ 
young Rathbun set about the collection and study of the 
Silurian fossils occurring in the sandstones and lime- 
stones at Medina, Albion and Lockport, New York. 

In these early years, before he was nineteen years of 
age, he founded the collection of paleontology in the 
museum of the Buffalo Society of Natural Sciences, and 
was appointed curator of that section of the museum. 
At the age of nineteen Rathbun entered Cornell Univer- 
sity and continued his paleontological studies under the 
direction of Charles Fred Hartt. Here he remained for 
two years, devoting himself largely to the study of a 
collection of Devonian and Cretaceous Brachiopods 
and Lamellibranchs from Brazil. The results of these 
studies are embodied in Rathbun’s earliest scientific 
papers. 

The first of these, on the Devonian Brachiopoda of 
Ereré, provinee of Para, Brazil, was completed at Albany 
with the assistance of Professor James Hall and pub- 
lished in the Bulletin of the Buffalo Society of Natural 
Sciences. In this paper occur careful descriptions and 
illustrations of fifteen new species, while the remaining 
eight species of the collection are referred to previously 
described forms from North America. This paper was 
revised and elaborated four years later? to include the 

* References to bibliography are placed at the end of the paper. 


Am. Jour. Sc1.—Fourts Srrizs, Vor. XLVI, No. 276.—DrEcremsBeEr, 1918. 
37 


758 Richard Rathbun. 


results of Rathbun’s own collections and in it is incor- 
porated a discussion of the relationships of the Devonian 
fauna of Brazil and North America. 

The Devonian Trilobites and Mollusks of LEHreré, 
Province of Para, Brazil, collected by Professor Hartt in 
1870-71 are described i in a joint paper by Hartt and Rath- 
bun, published in the Annals of the Lyceum of Natural 
History, New York. 

The study of the Cretaceous fossils of the Hartt col- 
lection required access to the collections in the Museum of 
Comparative Zoology of Harvard College, and here 
Rathbun remained from 1873 to 1875. At the same time 
he served as assistant in Zoology at the Boston Society of 
Natural History. These studies resulted in a prelim- 
inary report on the Cretaceous Lamellibranchs, including 
detailed descriptions of twelve new species.t During the 
years 1875 to 1878 Rathbun served as geologist to the 
Geological Commission of Brazil, where he made a study 
of the geological formations and the scanty mineral 
resources of several different provinces. While in Brazil 
he published a report of these geological studies inelud- 
ing an account of his search for coal deposits and an 
extended survey of the coral reefs which lie along the 
coast.° 

Several additional papers recording the results of his 
work in Brazil were published between 1876 and 1879. 
In one of these® the arrangement and formation of the 
Brazilian coral reefs and the characteristic life of the dif- 
ferent faunal zones are explained with great clearness. 
The Extinct Coral Reefs at Bahia,’ and the Coral Reefs 
of the Island of Itaparica, Bahia, and of Parahyba do 
Norte’ are the titles of other articles on the same subject. 
His geological papers include an interesting description 
of the Brazilian sandstone reefs and the agencies con- 
cerned in their formation® and reviews of the current lit- 
erature on the geology of Brazil.1° 

After Professor Hartt’s death from yellow fever early 
in 1878, Rathbun returned to the United States and pre- 
pared two papers describing the life and scientific work 
of his honored friend and teacher."' 

Rathbun had already acquired some experience in the 
investigation of marine life from his connection with the 
exvlorations of the U. S. Fish Commission as voluntary 
scientific assistant during the summers of 1874 and 1875, 


Richard Rathbun. 759 


and on his return from Brazil in 1878 he again joined 
the Commission as a regularly appointed scientific 
assistant. His interest was thereby diverted from the 
paleontological field to that of recent animal life, and 
from this time on his zoological papers deal exclusively 
with living forms. 

He first followed Alexander Agassiz, with whom he had 
been associated at Harvard, in the study of Echinoids, 
and his first paper in this new field comprises a list of 
eleven species of Hchinoids from the coast of Brazil.!? 
This was followed by a more detailed account of the geo- 
graphical distributions of all the species of echinoderms 
known from that locality’? with descriptions of species 
new to science. Other papers on echinoderms include 
reports upon the echini and stalked crinoids collected by 
the U.S. F. C. steamer Albatross in the Caribbean Sea 
and Gulf of Mexico,'* the species of starfishes of the 
genus Heliaster represented in the U. S. National 
Museum,'® and a catalogue of the collection of recent 
echini in the U. 8S. National Museum, with notes on geo- 
graphical distribution.'® 

Rathbun’s connection with the U. S. Fish Commission 
continued until 1896, during which time he published 
numerous papers describing the results of dredging 
expeditions off the eastern and southern coasts of the 
United States, and some of the new species of various 
groups of invertebrates secured. 

In 1879-1880 he was detailed to New Haven, where, 
under the direction of Professor Verrill, he prepared 
many duplicate sets of the various species of marine 
invertebrates represented in the Fish Commission’s 
extensive collections for distribution to museums and 
other institutions of learning. At the same time he ~ 
served as Assistant in Zoology at Yale, but in the follow- 
ing year the work was transferred to Washington. where 
he was appointed curator of the Department of Marine 
Invertebrates of the U. S. National Museum. Three 
large series of these sets were eventually prepared and 
the lists of species in each published in the Proceedings 
of the U. S. National Museum.17 

Under Rathbun’s direction collections of marine in- 
vertebrates were later prepared by the National Museum 
for various exhibitions. The catalogue cf the collec- 
tion of economic crustaceans, worms, echinoderms and 


760 3 Richard Rathbun. 


sponges for the Great International Fisheries Exhibition 
at London in 1883'® contains an excellent account of the 
economic importance of these groups and the industries 
in which they are concerned, while another catalogue!® 
describes the collection illustrating the scientific investi- 
gation of the sea and fresh waters. He also prepared 
and published the records of the dredging stations of the 
U. 8. Fish Commission for many years, in part with the 
cooperation of Sanderson Smith.?° | 

During this period Rathbun continued his systematic 
studies on various groups of invertebrates, publishing 
annotated lists of corals in the U. S. National Museum, 
with diagnoses of a number of new species! and a cat- 
alogue of the marine fauna of Provincetown, Mass.?* He 
was also interested in the parasitic copepods, of which 
he published a list of the species in the United States 
National Museum?? and described many new forms.** 

In the economic aspects of marine biology Rathbun 
produced the best of all his zoological work, and rendered 
a great service both to science and industry. His 
account of the natural history of crustaceans, worms, 
radiates and sponges?> in Goode’s Natural History of 
Aquatic Animals, published in connection with the Tenth 
Census, is a work of the highest excellence. This was 
followed by three extensive reports on the history and 
methods of the fisheries. Of these, the first deals with 
the crab, crayfish, lobster, shrimp and prawn fisheries,”° 
the second with the leech industry and trepang fishery,** 
and the third on the sponge fishery and trade.** Other 
reports published in connection with the Tenth Census 
include an account of the various fishing grounds of 
North America,?® and a survey of the ocean tempera- 
tures of the eastern coasts of the United States.2° Alto-- 
gether these reports comprise 550 quarto pages and 106 
plates, and they form one of the most important of all 
contributions to marine economic zoology. 

Other economic papers include notes on the decrease 
of lobsters.2! lobster culture.®? transplanting of lobsters. 
to the Pacific Coast,?? the shrimp and prawn fisheries,** 
methods of deep-sea dredging,®® investigations by the 
schooner Grampus,** a review of the fisheries in the con- 
tionous waters of the State of Washineton and British 
Columbia.’ and an introduction to the report on the Alba- 
tross explorations in Alaska,** in addition to yearly con- 


ae ET Te 


Richard Rathbun. 161 


tributions to the reports of the U. S. Commission of Fish 
and Fisheries from 1888-1896 respecting food fishes and 
the fishing grounds. ‘That he could also write in a popu- 
lar manner is shown by his articles on the ‘‘Giant 
Squid,’’®? and ‘‘The United States Fish Commission.’”° 

Rathbun’s publications by no means represent his 
major service to the Fish Commission, for his duties as 
chief executive officer and in charge of the scientific work 
of the Commission, in addition to several terms as acting 
commissioner, gave him the opportunity, for which he 
was so well fitted, of devising and directing the scientific 
investigations of the entire staff. To his skillful man- 
agement much of the practical success of the Commission 
previous to 1896 is due. 

Very important services to economic zoology were ren- 
dered by him in preparing the evidence for the case 
of the United States in the Paris fur seal Tribunal, in 
arranging for yearly surveys of the fur seal population 
in the Bering Sea, and later as the United States repre- 
sentative on the ‘‘ Joint Commission with Great Britain 
relative to the preservation of the fisheries in waters 
contiguous to the United States and Canada.’’ During 
these years (1891-1896) the fisheries conditions were very 
thoroughly investigated and an extended report pub- 
lished by Congress.** 

In 1896 Rathbun severed his connection with the Fish 
Commission and entered upon the administrative service 
of the Smithsonian Institution, of which he was appointed 
Assistant Secretary early in 1897. His natural gener- 
osity caused him to devote more and more of his time 
and energies to his executive duties and from 1899, when 
he was placed in charge of the National Museum, he had 
little opportunity for original investigations. 

His later writings were mainly limited to his adminis- 
trative reports of the National Museum*? during the 
years 1899 to 1917 in which he displayed great skill 
in the forceful presentation of the details required. To 
the building up and exhibition of the priceless collections 
of this great national institution and to the encourage- 
ment of its scientific research he gave his entire time and 
thonght for upwards of twenty years. 

His last publications relate to the culminating efforts 
of his hfe—the great new natural history building of the 
National Museum‘? and the national gallery of art,** 


762 Richard Rathbun. 


together with a paper of historical interest on the history 
of the Columbian Institute for the Promotion of Arts and 
Sciences.*® 

On the day of Dr. Rathbun’s death, July 16, 1918, the 
staff of the Smithsonian Institution recorded ‘‘their pro- 
found sorrow at the loss of a sincere friend, an executive 
officer of marked ability and one whose administration 
has had a wide influence upon the scientific institutions 
of the nation.’’ 

To his far-sighted wisdom, administrative ability, and 
untiring zeal systematic and economic zoology owe much, 
and to him the American public for generations will be 
indebted for an exposition of natural history which has 
few rivals. 

For-a brief account of the personal side of Dr. Rath- 
bun’s life, his success as an executive of the U. S. 
Fish Commission, Smithsonian Institution and National 
Museum, together with the honors which were accorded 
him, the reader is referred to Dr. Mareus Benjamin’s 
recent paper in Science.*® 

Richard Rathbun’s scientific career may be summar- 
ized in a few words; a youthful enthusiast in paleon- 
tology, an investigator of the Devonian and Cretaceous 
deposits and the coral reefs of Brazil, a contributor to 
systematic paleontology and zoology; in middle life a 
leading authority on the economic aspects of marine 
zoology and the means of its investigation; but most 
prominently and gratefully recognized in his full matur- 
ity for his remarkable ability in the administration of 
the United States National Museum; to him in large 
measure the successful development of ‘this ereat national 
center of research and exposition is due. 


Wes.ey R. Cor. 


BIBLIOGRAPHY. 


1Vol. 1, No. 4, 236-261, pl. 8-10, 1874. 

? Proc. Boston Soc. Nat. Hist., 20, 14-39, 1878. 

* Viol, ddj) 4410-027, A875: 

Proc. Boston Soc. Nat. Hist., 1874, 17, 241-256, 1875. 

5 Archivos do Museu Nacional do Rio de Janeiro, 3, 159-183, 1878. 

®° Amer. Naturalist, 13, 539-551, 1879. 

7 Loe. cit., 10, 439-440, 1876. 

® Proc. Boston Soc. Nat. Hist., 20, 39-41, 1878, and this Journal, 3d Ser., 
17, 326-327, 1879. 

® Amer. Naturalist, 13, 347-358, 1879. 


Richard Rathbun. 763 


This Journal, 17, 464-468, 1879; and 18, 310-311, 1879. 

1 Sketch of Professor C. F. Hartt, in Pop. Sci. Monthly, 13, 231-235, 
1878, and Sketch of the life and scientific work of Professor Charles Fred 
Hartt, in Proc. Boston Soe. Nat. Hist., 19, 338-364, 1878. 

” Additions to the Hchinoid fauna of Brazil, this Journal, 3d Ser., 15, 
82-84, 1878. 

13 A list of the Brazilian Echinoderms, with notes on their distribution, 
ete. Trans. Conn. Acad., 5, 139-158, 1879. 

* Proc. U. S. Nat. Mus., 8, 83-89, 606-620, and 628-635, 1885. 

* Loe. eit., 10, 440-449, pl. 23-26, 1887. 

6 Loc. cit., 9; 225-293, 1886. 

“ Loe. cit., 2, 227-232, 1879; 4, 298-303, and 304-307, 1881. 

* Bull. 27, U. S. Nat. Mus., 107-137, 1884. 

* Loe. eit., 511-622. 

Ann. Rept. Comm. Fish and Fisheries for 1879, 559-601, and Bull. 
U.S. F.C. for 1882, 2, 119-131. 

*1°Proc. U. S. Nat. Mus., 10, 10-19, and 354-366, pl. 15-19, 1887. 

Loe. cit., 3, 116-133, 1880. 

*8 Loe. cit., 7, 483-492, 1884. 

*4 Loe. cit., 9, 310-324, pl. 5-11, 1886, and 10, 559-571, pl. 29-35, 1887. 

°° Fisheries and Fisheries Industries of the United States; prepared 
through the cooperation of the Commissioner of Fisheries and the Superin- 
tendent of the Tenth Census, by George Brown Goode, part 5, 759-850, pls. 
260-277, 1884. 

*6 Loe. cit., Sec. 5, 2, 629-810, 1887. 

** Loc. cit., 813-816. 

*S Loe. cit., 817-841. 

** Loe. cit., Sec. 3, vil-xviil, 5-154, 49 charts, 1887. 

*® Loe. eit., 155-238, 32 charts, 1887. 

Bull. U. S. F. C. for 1884, 4, 421-426. 

* Loe. cit., 1886, 6, 17-32. 

% Loe. cit., 1888, 8, 453-472, pl. 71. 

Loe. cit., 1882, 2, 139-152. 

*° Science, 4, 54-57, 146-151, 225-229, and 400-404, 1884. 

°° Collins, Bean and Rathbun, Bull. U. S. F. C. for 1887, 7, 217-267. 

*7 Rept. U. S. Commissioner of Fish and Fisheries 1899, 251-350, pl. 8-16. 

f bolly 8. B.C. 1888, 8,5-16. 

°° St. Nicholas, 8, 266-270, 5 pls. 1881. 

“Century Mag., 43, 679-697, 19 figs. 1892. 

“ Washington, D. C., 178 pp., 1897. 

“Reports of the Dept. of Marine Invertebrates, U. S. National Museum, 
in Annual Reports of the Board of Regents of the Smithsonian Institution, 
1883-1892 inclusive, and Reports U. 8S. Nat’] Museum (annually), 1899-1917. 

* Bull. 80, U. S. Nat’l. Museum, 134 pp. 31 pls., 1913. 

“ Bull. 70, U. S. Nat’l. Museum, 140 pp., 26 ills., 1909. 

* Bull. 101, U. S. Nat’l. Museum, 85 pp., 1917. 

Vol. 48, 231-235, Sept. 6, 1918. 


764 Scientific Intellugence. 


SCIENTIFIC INTELLIGENCE. 


I. CHEMISTRY AND PHYSICS. 


1. Notes on Isotopic Lead.—F RANK WIGGLESWORTH CLARKE 
has given an interesting discussion of the developments within 
the past few years in regard to the forms of lead produced by 
radioactive transformations. The forms of lead thus produced 
are identical with ordinary lead in their distinctively chemical 
properties, but they differ from it appreciably in atomic weight 
and in specific gravity. Thus the lead from the purest uranium 
minerals has an atomic weight fully a unit lower than that of 
ordinary lead, while that from thorium minerals is nearly a unit 
higher, and they are called isotopes of lead. Other cases of 
isotopes are believed to exist in connection with the temporary 
elements produced by radioactive transformations, but in no 
other cases is there evidence of any variation in the atomic 
weights of elements from different sources. In the case of ordi- 
nary lead it has been found that samples from various localities 
and different minerals give the same atomic weight within the 
limits of experimental error, that is, between 207-20 and 207-22, 
according to the results of Baxter and Grover. Samples of lead 
from uranium minerals have given varying results, some as low 
as 206-04 and 206-09, while a thorite lead gave 207-77. Since 
uranium minerals usually contain some thorium, and vice versa, 
and since contamination with ordinary lead is possible, there is 
some doubt about the actual atomic weights of these isotopes, 
and the rather wide variations in the results obtained for the 
atomic weights of radioactive lead is easily explained. 

The author criticizes the employment of the ratio between lead 
and uranium as first used by Boltwood for caleulating the age of 
uranium minerals, chiefly on the ground that a part of the lead 
present may be normal lead. Boltwood calculated the age of 
Connecticut uraninite to be 410,000,000 years, and that of Cey- 


lonese thorianite as 2,200,000,000 years. He criticizes the method - 


further from the fact that Becker in calculating the ages of 
minerals from Llano County, Texas, found enormously different 
ages for the same mineral from different analyses. For example, 
two analyses of fergusonite by Mackintosh gave the ages 
10,350,000,000 and 2,967,000,000 years. The author notes that 
Barrell and others defend the use of the lead-uranium ratio for. 
determining the age of minerals, and admits that the subject is 
still open to discussion.—Proc. Nat. Acad. Sct., 4,181. 8. L. w. 


2. The Recovery of Potash and Other Materials from Kelp.— 
When the supply of German potash salts was cut off in 1914, 
the kelp of the Pacific Coast of the United States attracted-much 
attention as a source of potash, and C. A. Hiearns has recently — 


Chemistry and Physics. 765 


given an account of the practical development of this idea. At 
first primitive methods, involving much manual labor, were used 
in harvesting the kelp, but later mechanical reaping devices with 
band conveyors were installed upon large power scows, so that 
the harvesting and unloading were accomplished much more 
economically by machinery. At first the kelp was dried and 
burnt to produce an ash, containing about 15 per cent of K,O, 
which was used for fertilizers. Afterwards the kelp was dried 
and only partially incinerated in order to save the greater part 
of the nitrogen contents of the material and thus increase its 
value as a fertilizer. In spite of improved methods, however, 
the production of potash from kelp has been found to be expen- 
sive, and the industry will be unable to compete with the usual 
European supply, nor even with our own supply from brines, 
alunite deposits, recovery from cement kilns, blast furnaces, etc., 
unless other products can be produced from the kelp. To 
accomplish this last purpose a factory was started in 1915 at San 
Diego, California, with the intention of producing acetone, pot- 
ash and iodine from kelp. For this purpose the kelp is first 
fermented, whereby acetic acid is formed and the potash and 
iodine are brought into solution. The acetic acid is neutralized 
with limestone, forming calcium acetate, which upon ignition 
yields the important solvent, acetone, while the iodine is saved 
and the potash is finally obtained as potassium chloride. As the 
process has developed other products have been made, so that this 
method appears to be a promising one. It is stated that not 
more than 25 tons per day, on the basis of 80 per cent muriate 
of potash, are produced by all the kelp-harvesting concerns at the 
present time, and that more than half of this is produced by the 
fermentation process.—Jour. Indust. Engr. Chem., 10, 832. 
me Li. |W 


3. Treatise on Applied Analytical Chemistry, by Vittorio 
VILLAVECCHIA. Translated by Thomas H. Pope. Vol. II, 8vo, 
pp. 9386. Philadelphia, 1918 (P. Blakiston’s Son & Co.).—The 
first volume of this excellent work, which has been prepared with 
the collaboration of nine other experts, was noticed and highly 
praised in the April number of the Journal of the present year. 
The present volume completes the work and deals with meat and 
its preparations, milk and its products, sugars and products con- 
taining them, beer, wine, spirits, and liquors, essential oils, tur- 
pentme and its products, varnishes, rubber and guttapercha, 
tanning products, inks, leather, coloring matter and textile fibers, 
yarns, fabrics. This volume, like its predecessor, has the excel- 
lent features of being clear, practical, and satisfactory in the 
selection of methods of analysis, and in giving valuable notes in 
regard to the interpretation of results. H. L. W. 


4. Outlines of Theoretical Chemistry ; by FREDERICK H. Ger- 
MAN. 8vo, pp. 5939. New York, 1918 (John Wiley & Sons, 


766 Scientific Intelligence. 


Inc.).—This is the second edition of an excellent text-book which 
first appeared five years ago. By means of a thorough revision 
and considerable amplification the present edition has been made 
to give a very satisfactory view of the recent advances in physical 
chemistry. The radioactive phenomena bearing upon our present 
atomic theory are well presented as is also the bearing of X-ray 
spectra upon crystalline structure, while the chapter on colloids 
has been re-written. The book gives a very clear and able 
account of theoretical chemistry, and the practical problems 
introduced at the conclusion of many of the chapters should be 
found very useful in connection with the study of the subject. 
H. L. W. 


0. LElectro-Analysis; by Epegar F. Smiru. 12mo, pp. 344. 
Philadelphia, 1918 (P. Blakiston’s Son & Co.).—This is the sixth 
edition of a work so well known and highly regarded among 
analytical chemists that no description of its general features 
need be given. Since the appearance of the last edition com- 
paratively few important advances have been made in this line 
of work, so that comparatively few additions to the text have 
been required. Among the more important additions is the 
description of an improved double cup for the purpose of analyz- 
ing mixtures of halides, which has been perfected in the author’s 
laboratory. It is believed that all the recent advances that may 
be considered reliable have been brought into the new edition. 

H. bL. W. 


6. Absorption of X-Rays wm Aluminum and Copper—A 
method for determining the coefficient of absorption of X-rays 
in elements, which seems to eliminate the chief sources of error 
(heterogeneity and variations in intensity of the radiations) 
usually affecting the results, has been devised and tested by 
C. M. WILLIAMS. 

In order to obtain a homogeneous beam the rays from a Cool- 
idge tube were analyzed by a rock-salt ‘‘grating.’’ The inclusion 
in the first-order beam of shorter wave-lengths of higher orders 
was prevented by using too low a voltage to excite the submul- 
tiple radiations. In the paper, lines are plotted with thickness 
of absorber as abscissa and logarithm of ionization current as 
ordinate, each line corresponding to a different applied voltage. 
The length of the alternative spark-gap, between polished metal 
spheres 1 em. in diameter, was taken as a measure of the voltage. 
The lines for 12, 9, and 6 ems. spark-gap show decided curvature 
and hence superposition of several wave-lengths. The line for 
3 ems. is, on the other hand, perfectly straight thus indicating 
a homogeneous beam. 

In order to compensate for the fluctuations in intensity of the 
source a special form of ionization chamber was constructed. 
The innovation consisted in separating the ionization chamber 
into upper and lower halves or compartments by a horizontal, | 


Chemistry and Physics. 767 


longitudinal metal plate. Each compartment was provided with 
its own insulated electrode. The axis of the ‘‘reflected’’ beam 
of homogeneous rays coincided with that of the ionization cham- 
ber so that equal portions of the beam entered the upper and 
lower compartments. The layers of absorbing material were 
placed in front of the upper compartment but not the lower. 
Readings of the electroscope were taken first with the upper elec- 
trode joined to it and then with the lower one connected with 
it. In this way the lower compartment furnished the data neces- 
sary for the standardization of the readings taken with the upper 
compartment and its associated absorbing screens. ‘‘ Very con- 
sistent results were obtained in this way, the points all lying very 
evenly on a straight line—indeed, the results for the absorption 
coefficient obtained in independent experiments rarely varied by 
more than 1 per cent., or very occasionally by 2 per cent.’’ 

The mass-absorption coefficient »/p is tabulated, for aluminium 
and copper, for eight wave-lengths extending from 0-431 « 10-° 
to 0-627 & 10 em. When p/p for copper is plotted against p/p 
for aluminium, segments of two sensibly parallel straight lines 
are obtained. ‘The break in the locus occurs at about A = 0-49 A 
(coef. = 2) which fact is very significant since Barkla found 
evidence of the emission by aluminium of a J radiation corre- 
sponding to a mass-absorption coefficient approximately equal 
to 19. Finally, the formula p/p=aaA"+C gave excellent 
agreement with the experimental data. For aluminium and 
copper the values of » were found to be 3 and 5/2 respectively. 
The latter datum is quite exact and it agrees with Owen’s fifth- 
power law of absorption.—Proc. Roy. Soc., 94 A, 567, 1918. 

iS ier Se Bh 


7. Flame and Furnace Spectra of Iron—F rom his exhaustive 
investigations of the tube-furnace spectrum of iron A. S. King 
has deduced values for the effective temperatures of the follow- 
ing flames: air-coal gas (mantle), oxy-hydrogen, oxy-coal gas, 
oxy-acetylene, and air-coal gas (cone). Since these values differ 
markedly from the values obtained directly by E. Bauer, who 
worked with the same flames that had been studied spectroscop- 
ically by Hemsalech and de Watteville, the whole question has 
been recently subjected to a very thorough investigation by G. A. 
HemsauecH. The discrepancies were due, at least in part, to the 
fact that King used a high-dispersion grating spectrograph while 
Hemsalech and de Watteville employed an ordinary prism appa- 
ratus. Consistent results were obtained as soon as Hemsalech 
set up his own tube-furnace and made all spectroscopic observa- 
tions of both the flame and the furnace spectra with the same 
spectrograph. 

The conclusions at which Hemsalech arrived may be sum- 
marized in the following sentences: 

(a). The spectra of iron given by an electric-tube resistance 


768 Scientific Intellagence. 


furnace at atmospheric pressure, and at temperatures up to about 
2400° C., are due to the action of heat on a chemical compound 
of the metal and not on the uncombined metal alone. Therefore 
these spectra are not of purely thermal origin. 

(b). A spectrum of iron has been observed at the low tem- 
perature of 1500° C. and found to be the same as that emitted 
by an air flame burning in coal gas. 

(c). The spectra of iron compounds in flames are identical 
with the furnace spectra at corresponding temperatures up to 
about 2400° C. All the lines of evidence lead to the conelusion 
that the mode of excitation must be the same in the two eases, 
namely, chemical dissociation of an iron compound by thermal 
action. 

(d). The character of the spectrum is independent of the 
nature of the iron compound; thus chlorides, oxides, ete., always 
give the same kind of spectrum in either the flame or furnace at 
a given temperature. 

(ec). The name thermo-chemical excitation has been suggested 
to designate the cause of emission of the spectra in question. 
These spectra differ completely from the spectra radiated by the 
same compounds in the explosion region of the air coal-gas flame 
in which the emission is due to chemical excitation at a com- 
paratively low temperature. 

(f). The aluminium lines at A3944 and A8962 have been ~ 
observed at the low temperature 1500° C.—Phil. Mag., 36, 209, 
1918. Hh) Secu 


8. Publications of the American Astronomical Society; Vol- 
ume 3. Pp. 372. 1918 (Published by the Society).—This 
volume contains the reports of the meetings of the society, begin- 
ning with the sixteenth (1913) and ending with the twenty-first 
(1917). In the majority of cases the scientific papers presented 
at the several meetings are given in abstract form. The chief 
exceptions to this general statement are afforded by the address 
(March, 1914) by Henry Norris Russell, on the ‘‘ Relations 
between the Spectra and other Characteristics of the Stars,’’ and 
by the reports of the committee on stellar parallaxes. Pages 347 
to 372 contain the constitution and by-laws, lists of the officers 
and members, author and subject indexes, ete. The unavoidable 
uniformity of the text is greatly relieved by eight full-page, half- 
tone reproductions of excellent photographs of the members 
present at the meetings, of Percival Lowell, and of certain new 
astronomical observatories. | HL Sean s- 


Il. Gronoey. 


1. Maryland Geological Survey; Epwarp B. Maruews, State 
Geologist. Vol. X. Pp. 553, 96 text. figs., 19185 jand, Amne 
Arundel County. Pp. 232, 9 pls., 4 text figs., atlas of 4 maps, 


Geology. 769 


1917.—The first of these elegant volumes begins with a portrait 
and appreciation of the late William Bullock Clark, who during 
the years from 1896 to 1917 did so much to place the state of 
Maryland in the front rank among the state geological surveys 
of our country. The many volumes issued under the directorship 
of Professor Clark will always remain his monument, attesting 
to his high standard in scientific work and his inspiration to 
others. 

Volume ten deals with the geography of Maryland, including 
also the physiography, natural resources, manufactures, etc. (pp. 
39-167). Part II, the larger one, deals fully with the surface and 
underground water resources of Maryland, including Delaware 
and the District of Columbia. Part I is by Professor Clark. Part 
II by the same author assisted by EK. B. Mathews and E. W. 
Berry. The whole is a report that should be of the greatest 
practical value to the state. 

The physiography, geology, and mineral resources of Anne 
Arundel County are described at length by Homer P. Little. 
The volume also contains accounts by others of the soils, climate, 
hydrography, magnetic declination, and forests. (CHS 


2. The San Lorenzo Series of Middle California; by Bruck 
L. CuarK. Bull. Dept. Geology, University of California, vol. 
11, No. 2, pp. 40-234, pls. 3-24, 4 text figs., 1918.—This excel- 
lent memoir describes the stratigraphy and fauna of the Oligo- 
cene of central western California, and compares it with similar 
formations of Oregon, Washington, and British Columbia. The 
fauna consists of 137 species, of which 70 are described here as 
new; nearly all are of bivalves and gastropods. 

The presence of Oligocene strata in California was demon- 
strated by Arnold in 1906, and now they are known to have a 
wide distribution along the west coast of the United States. 
From the Miocene, the Oligocene is separated by a time break 
of apparently long duration, and but 9 per cent of the fauna 
passes upward, while with the Eocene it is intimately connected. 
In fact, the author believes that a part of the Oligocene as here 
defined may include strata that are actually of Upper Eocene 
age, although no fossils are common to the two series. Not a 
single species is common to the Atlantic and Pacific borders of 
North America, and but 2 per cent of the fauna is still living. 

Gus: 


3. West Virgina Geological Survey; I. C. Wutrts, State 
Geologist, Morgantown, W. Va.—The following important publi- 
cations have been recently issued: 


No. 28. Detailed Report on Barbour and Upshur Counties and 
Western Randolph; by D. B. Recsr, with an introductory discus- 
sion of deep well records, including the Deepest Well in the World, 
by I. C. Wurre, and a discussion of deep well temperatures by 
C. E. Van Orstranp. Pp. civ, 867; 53 pls., 48 text figs., with 


770 Scientific Intellugence. 


4 maps (topography and geology) in separate case. These maps 
cover respectively Barbour county, and Upshur county and the 
coal area of Randolph west from Big Laurel and Rich Mountains. 
The whole region is underlain by the Coal Measures in which are 
several valuable beds, all of which are described, analyzed, and 
their areas mapped in this report. Price (including ease of 
maps, delivery charges prepaid), $3.00. Extra copies of geologic 
map of Upshur and Western Randolph, $1.00; of Barbour, 75 
cents; of topographic map of Upshur and Western Randolph, 
iis cents ; of Barbour, .50 cents. 

No. ik: Revised Figure showing Bituminous Coal Beds in 
West Virginia. Section, 6 inches wide and 40 inches long, 
showing the names, number and intervals separating the Coal 
beds of West Virginia, and extending from the top of the Dunk- 
ard Series to the base of the Pottsville Series, on the scale of 
1 inch to 200 feet, compiled and revised to July 1, 1918; by Ray 
V. Hennen, Assistant Geologist. Price, 25 cents. 


4, The Evolution of the Earth and tts Inhabitants; by 
JOSEPH BARRELL, CHARLES ScHUCHERT, L. L. Wooprurr, R. S. 
Luu, and EuuswortH Huntineton. Pp. 208, 4 pls., 38 text 
figs. Yale University Press, 1918 ($2.50)—During the winter 
of 1916-1917, the Yale Chapter of the honorary scientific society 
of the Sigma Xi, under the presidency of Professor Richard 8. 
Lull, presented a series of popular lectures on the geological and 
biological evidences for the evolution of our planet and its life. 
These are now published in book form. The lectures are: 1, The 
origin of the earth, by Professor Barrell; 2, The earth’s chang- 
ing surface and climate, by Professor Schuchert; 3, The origin 
of life, by Professor Woodruff; 4, The pulse of life, by Professor 
Lull; and 5, Climate and civilization, by Doctor Huntington. 
They ought to be of wide interest in scientific circles. The book- 
making is of the best. 


dD. Hqude of the Oligocene, Miocene, and Pliocene of North 
America, Iconographic type revision; by HEnry FAIRFIELD 
Osporn. Mem. American Museum of Natural History, new 
ser., vol. 2, pt. 1, 329 pp., 54 pls., 173 text figs., 1918—This 
imposing quarto gives an admirable summary of our knowledge 
of the American fossil Equidze from the Oligocene to the Pliocene 
inclusive. It consists of the usual preface, a summary of the 
head and limb ratios and indices used in the work, and an expo- 
sition of tooth morphology. Then follows a deseription of the 
chief geologic horizons, formations, and levels which contain 
equine remains, together with the principal geographical local- 
ities, all of which is summarized on page 35. 

The systemic portion of the work is the most extensive and 
embraces every known species, reference to the original deserip- 
tions, the horizon and locality, the repository and description of 


Miscellaneous Intelligence. 771 


the type, the specific characters and, especially, carefully drawn 
figures showing the essential features of tooth, skull, and limb, 
which, as all students of our science know, are worth any amount 
of verbal description. Not only are the text figures ample, but 
they are supplemented by the beautifully drawn and contrast- 
ingly arranged figures of the plates. 

This very real contribution to vertebrate paleontology is but 
a forerunner of a promised monograph of the Equidze which 
Professor Osborn has had in preparation since 1900. R. S. L. 


6. The genus Homalonotus; by F. R. Cowper Reep. Geol. 
Mag., n. s., dec. 6, vol. 5, pp. 263-276, 314-327, 1918—The author 
has carefully restudied all of the species of Homalonotus with a 
view of a better generic classification of these trilobites. He 
recognizes but a single genus, Homalonotus, and ten subgenera. 
Of these three are new—Kohomalonotus, Brongmartella (to 
replace the preoccupied Brongmartia of Salter), Burmeisterella, 
and Parahomalonotus. The genotype of Homalonotus is H. 
knighti, and even though the author is well aware of this, he 
uses the form again as characteristic of Koenigia, in this follow- 
ing Salter 1865. According to the rules of nomenclature this 
cannot be done, and Koenigia becomes a synonym of Homalonotus 
sensu stricto. The reviewer recognizes, however, that this auto- 
matie action under the rules does not express Professor Reed’s 
view, as H. knighti is a very specialized form of these trilobites. 

Cs 


Ill. Miscetnaneous ScrentiFic INTELLIGENCE. 


1. Dispensaries, their Management and Development; by 
Micuareu M. Davis, Jr., and ANDREW R. WARNER. Pp. ix, 438. 
New York, 1918 (The Macmillan Company ).—Maintaining that 
conditions after the war will result in reconstruction of medical 
service in the direction of medical organization rather than of 
medical individualism, the Dispensary is presented as the medical 
organization which must cover the major portion of the field in 
caring for disease, standing between the hospital and the Public 
Health Department. The hospital cares for the acutely incapa- 
eitated, the Public Health Department deals usually with preven- 
tive work alone. But the Dispensary is an institution which 
organizes the professional equipment and special skill of physi- 
cians for the diagnosis, treatment and prevention of disease 
among ambulatory patients. 

The book is divided into three parts—the history and present 
extent of dispensaries in the United States; the equipment, 
organization, and daily conduct of dispensaries; the presentation 
of the dispensary as a form of organization for rendering 
efficient medical service to the people. A. F. M. 


112 Scientific Intelligence... 


2. Principles and Practice of Filling Teeth; by C. N. JoHN- 
son. Fourth Edition.. Pp. xii, 286. Philadelphia, 1918 (P. 
Blakiston’s Son & Co.).—A new edition of a popular treatise on 
the technique of the subject by the editor of ‘‘The Dental 
Review.’’ The author states that the subject of oral prophylaxis 
has been given added attention. His good judgment is attested 
by the following quotation: ‘‘The mania for smoothness and 
evenness which impels an operator to grind down all small 
prominences on the teeth is reprehensible in the highest degree. 
This is not prophylaxis; it is vandalism.’’ L. B. M. 


3. A Study of Engineering Education; by CHARLES Ripore 
Mann. Prepared for the Joint Committee on Engineering Edu- 
eation of the National Engineering Societies. Carnegie Founda- 
tion for the Advancement of Teaching. Bulletin No. XI. Pp. 
xi, 189. New York City (576 Fifth Avenue), 1918.—This recent 
bulletin of the Carnegie Foundation presents the results reached 
by four years work of the joint committee mentioned above. The 
contents are summarized in part as follows: ‘‘The origin of the 
present system of engineering schools is traced in detail, and its 
characteristics, both good and bad, are frankly stated. Its opera- 
tion is studied mainly from the point of view of the effect upon 
the student and there is a careful examination of entrance records 
and college courses, as well as a brief summary of the current 
methods of instruction. On the basis of this analysis of the 
present situation, the larger problems of engineering education 
are considered to be those of admission, content of courses, fac- 
ulty organization, and curriculum. The treatment culminates 
in a definition of each of the larger problems in terms of the 
requirements of the profession and of the young men who wish 
to enter.’’ | 

‘‘Numerous suggestions are presented as to ways and means 
of solving the problems thus defined, in an effort to reach the 
general principles which seem best qualified to help each school 
in solving the problem according to its own peculiar cirecum- 
stances. Among the suggestions may be mentioned the necessity 
for more objective methods of rating and testing students and 
more accurate records of achievement; the need for closer 
cooperation among the several departments of instruction at each 
school; the introduction of practical experience with engineering 
materials into the Freshman year; and the increase in the 
emphasis placed upon the humanities and humanistic studies.’’, 


4. National Academy of Sciences—The autumn meeting of 
the National Academy was held on November 18, 19, at the Johns 
Hopkins University, Baltimore. oj 


ai tea ee} CURSE St: g-+ 


a 


INDEX TO VOLUME XLVI.* 


| 


Academy, National, meeting, at 
Baltimore, 772. fi, 
Airplane Characteristics, Bedell, 


Gi. 
Alaska, Paleozoic glaciation, Kirk, 
Gir. 
Aluminum, absorption of X-rays, 
Williams, 766. 

American Journal of Science, 1818- 
Tio, Wana, I. 
Astronomical Society, American, | 
768. | 
Astronomy, Young, 542. | 


Barrell, J., growth of knowledge of 
earth structure, 133. | 
Bedell, F., Airplane Characteristics, | 


601. 

Benson, W. N., origin of serpen- | 
tine, 603. 

Blake, J. M., solving crystal prob- 
lems, 651. 

Botany, development since 1818, 


Goodale, 399. 


Browning, P. E., separation of ger- 


manium, 663. 
Butts, C., geologic section of Benne 
sylvania, 523. 


C 
Canada, Dept. of Mines, 
tions, 477. 
— geol. survey, 477, 5 
Carnegie ofdation, “Bulletin x 1s 


1/2: 

Genbary of Science, 1818-1918, I et 
seq. 

Ceramic Society, Journal, 6109. 

Chemistry, Hildebrand, 614. 

— Analytical, Getman, 765. 

— — Villavecchia, 765. 

— of Foods, Sherman, 548. 

— Inorganic, Mellor, 541. 

— Laboratory Manual, Blanchard 
and Wade, 542. 

— of Proteiris, Robertson, 548. 

— progress of, 1818-1918, Wells and 
Foote, 259. 


CHEMISTRY. 
Arsenic and Antimony, com- 
pounds of, Morgan, 615. 
Barium and strontium, separa- 


tion, Gooch and Soderman, 538. 
Germanium, separation, Brown- 


publica- | 


Hypophosphates, preparation, 
Van Name and Huff, 587. 

Iodides, detection, Curtman and 
Kaufman, 614. 

Lead, isotopic, Clarke, 764. 

Molecular frequency, Allen, 544. 

— weights, apparatus for deter- 
mining, Chapin, 613. 

Osmium, new reaction, 
gaeff, 680. 

Periodic table, Hackh, 481. 

Potash from kelp, recovery of, 
Higgins, 764. 


Tschu- 


Soils, organic matter in, Rather, 
688. 
Vanadic acid, determination, 


Gooch and Scott, 427. 
Vanadium in sedimentary rocks, 
Phillips, 473. 
Vapors in gases, estimation of, 
Ek Ss, and M. D. Davis, 688. 
Zine, determination of, Jamieson, 


614. 


Coal beds in West Virginia, Hen- 
nen, 770. 

Coe, W. R., a century of zoology in 
America, Bp Ree MOLICe. s Oke tt ke: 
Rathbun, 757. 

‘Colorado mineral springs, radio- 
active properties, Lester, 621. 
Cramer, W., Chemical Physiology 

549. 

Cristobalite, melting point, Fergu- 
son and Merwin, 417. 

Crystal problems, Blake, 651. 

Cycads, American fossil, part VIII, 
Wieland, 645. 


Dana, E. S., American Journal of 
Science, 1818-1918, TI. 

Davis, M. M., Jr., Dispensaries, 771. 

Davis, W. M., Cedar Mt. trap ridge 
near Hartford, 476; notice of, 
G. K. Gilbert, 660. 

Dispensaries, Davis and Warner, 


771. 

Dunbar, C. O., Devonian of West 
Tennessee, 732. 

Dustfall of March 9, 1918, Winchell 
and Miller, 590. 


E 
Earth, Evolution of, Barrell, Schu- 
chert, etc., 770. 


ing and Scott, 663. 


* This Index contains the general heads, 


Electro-Analysis, Smith, 766. 


CHEMISTRY, GEOLOGY, MINERALS, OBITUARY, 


Rocks; under each the titles of Articles referring thereto are included. 


Am. Jour. Sct.—FourtH Series, VoL. XLVI, No. 276.—DrEcrEmBER, 1918, 


774 


Emery, W. B., Green River desert 
section, Utah, 551. 

Engineering Education, Mann, 772. 

Epsomite, spotted lakes of, Jenkins, 
638. 

Equidz of North America, Osborn, 


770. 
Evolution of Earth, 770. 
— in medicine, A’dami, 601. 


F 
Ferguson, J. B., melting points of 
cristobalite and tridymite, 417. 
Field Museum, publications, 470. 
Foote, H .W., progress of chemis- 
try, 1818-1918, 259. 
Ford, W. E., growth of mineralogy, 
1818-1918, 240. 


G 
GEOLOGICAL REPORTS. 
Canada, 477, 547. 

Maryland, 768. 
West Virginia, 760. 
Geological surveys, Government, 
1818-1918, Smith, 171. 
Geology, history, 1818-1918, Schu- 
chert, 45; Gregory, 104; Barrell, 
133; Luil, 193. 


GEOLOGY. 


Cedar Mt. trap ridge near Hart- | 


ford, Davis, 476. 

Cretaceous age of the “Miocene 
flora” of Sakhalin, Kryshtofo- 
vich, 502. 

Devonian of West Tennessee, 
Dunbar, 732. 

Equidze, Osborn, 770. 

Geologic section of Pennsylvania, 


Butts, 523. 

Glaciation, Paleozoic, Alaska, 
ice ys i, 

Green River desert section, Utah, 
Emery, 551. 


Homalonotus, Reed, 771. 
Lopolith, Grout, 516. 
Mysticocrinus, Springer, 666. 
Onaping map area, Collins, 547. 
Oregon Cascades, ‘Smith, 546. 
Plants, Fossil, Seward, A75. 
Pliocene history of Mississippi, 
Shaw, 547. 
Rhode Island geology, Hawkins, 
437. 
San Lorenzo series of middle 
‘California, @lark, 760: 
Timiskaming County, Quebec, 
Wilson, 547. 
Geophysical Laboratory, Washing- 
ton, work of, Sosman, 255. 
Getman, F. H., Chemistry, 765. 


INDEX. 


Gilbert, G. K., obituary notice, 
Davis, 660. 

Gooch, F. A., determination of 
vanadic acid, 427; barium and 
strontium, separation, 538. 

Goodale, G. L., development of 
botany since 1818, 3090. 

Gregory, H. E., progress in inter- 
pietation of land forms, Io4. 

Grout, F. F., lopolith, 516. 


H 
Hackh, I. W. D., modification of 
the periodic table, 481. 
Hawkins, A. C., geology of Rhode 
Island, 437. 
Helvetica, Chimica Acta, 480. 
‘Hildebrand, Jive; Chemistry, 614. 
Hopewell- Smith, AS Histology of 
the Mouth, 480. 
Huff, W. J., preparation of hypo- 
phosphates, 587. 


Jenkins, O. P., 
epsomite, 638. 

Johnson, C. N., Teeth, 772. 

Jonson, E., law of dissipation of 
motion, 578. 


spotted lakes of 


Kirk, E., Paleozoic glaciation in 
Alaska, 511. 

Kryshtofovich, A. N., Cretaceous 
age of the “Miocene flora” of 
Sakhalin, 502. 


L 

Lecithin, Maclean, 549. 

Lester, O. C., radioactive mineral 
springs of Colorado, 621. 

Light, scattering of, by dust free 
air, Strutt iors 

Lull, R. S., development of verte- 
brate Paleontology, 193. 


M 

Maclean, H., Lecithin and Allied 
Substances, 540. 

Mann, C. R., Engineering Educa- 
tion, WGek 

Mansfeld, Gu Rk; areatete phos- 
phates of the U. S:7 50. 

Maryland oe ‘survey, 768. 

Mellor, J. W., Inorganic Chemistry, 
Moen H. E., melting points of 
cristobalite and tridymite, 417. 
Metals, Chemical Combinations, 

Giua and Robinson, 689. 
Miller, E., Origin of Planetary Sys- 
tem, 542. 


INDEX. 


Miller, E. R., dustfall of March 9, 
1918, 599. 

Mineralogy, 1818-1918, Ford, 240. 

= op eiacee wake Area, Quebec, 
Poitevin and Graham, 479. 


MINERALS. 
Colerainite, 470. 
Cristobalite, 417. 
Epsomite, 638. 
Periclase, California, 581. 
Serpentine, 603. 
Stichite, 479. 
Tridymite, 4 

Mitchell, C. te Edible Oils and 
Fats, 615. 

Morgan, G. T., Arsenic and Anti- 
mony, 615. 

Motion, law of dissipation, Jonson, 


578. 
Mouth, Histology, Hopewell-Smith, 
480. 


N 
New York State Museum, Report, 
Clarke, 545. 


OBITUARY. 
Eastman, C. R., 692. 
Gilbert, G. K., 660. 
Hidden, W. E., 480. 
Irving, J. D., 550. 
Peckham, S. F., 620. 
Pedler, A., 480. 
Phillips, W. B., 692. 
Rathbun, R., 620. 
Trowbridge, C. C., 550. 
Walliams, H. S., 550. 
Williston, S. W., 620. 
Oils and Fats, Mitchell, 615. 
Oregon Cascades, geology, Smith, 
Osborn, H. F., Equidez, 770. 
546. 
Ozone and ultra-violet transpar- 
ency of the atmosphere, Strutt, 
543. Pp 


Page, L., a century’s progress in 
physics, 303. 

Paleontology, vertebrate, develop- 
mrent. Lull, 193. 

Pennsylvania, geologic 
Butts, 523. 

pete table, modification, Hackh, 
481. 

Petrology, rise of, Pirsson, 222. 

Phillips, A. H., vanadium in sed- 
imentary rocks, 473. 

Phosphates of the Western United 
States, Mansfield, 5o1. 

Physics, a century’s progress, Page, 
303. ; 

— Experiments i 
MacNutt, 618. 


section, 


n, Franklin and 


TT5 


Physiology, Chemical, Cramer, 549. 

Phytopathology, Whetzel, 540. 

Pirsson, ie Vien tise OL Petrology as 
a science, 222. 

Planetary System, Origin, Miller, 
542. 

Potential measurements, switch for, 
White, 610. 


R 
Radioactive mineral springs of Col- 
Ofado, 621. 
Rathbun, R., and his contributions 
to zoology, 757. 
Rhode Island, geology, Hawkins, 


437. 
Robertson, T. B., Physical Chemis- 
try of Proteins, 548. 


ROCKS. 
Calcite-brucite rocks, Rogers, 582. 
Diabase, Rhode Island, 452. 
Gabbro, lopolith, Grout, 516; 
Rhode Island, Hawkins, 455. 
Green schist, Rhode Island, 440. 
Rogers, A. F., American occurrence 
of periclase, 581. 


Sakhalin, “Miocene flora” of, 
Kryshtofovich, 502. 

Sarawak Museum Journal, 479. 

Scott, S. E., separation of germa- 
nium, 663. 

Scott, W., determination of vanadic 
acid, 427. 

Schuchert, C., historical geology, 
Mole TOTS 45> MoOLice,, Of bl: oO: 
Williams, 682; Earth’s Changing 
Suptace,. 770; 

Science, Century of, 
et seq. 

— Elements of General, 
and Eikenberry, 600. 

Serpentine, origin, Benson, 603. 

Seward, A. C., Fossil Plants, 475. 

Sherman, H. C., Chemistry of 
Food, 548. 

Smith, E. A., Zinc Industry, 689. 

Smith, E. F., Life of James Wood- 
house, 541; Electro-Analysis, 766. 

Smith, G. O., century of govern- 
ment geological surveys, I71. 

Soderman, M. A., barium and stron- 
tium, separation, 538. 

Sosman, R. B., work of the Geo- 
physical Laboratory, Washing- 
ton, 255. 

Spectra, iron, King, 767. 

Spectrum, solar, occurrence of 
ultra-violet bands in, Fowler and 
Gregory, 617. 

Springer, F., Mysticocrinus, 666. 

Stoichiometry, Young, 680. 


1818-1918, I 
Caldwell 


776 INDEX. 


sl 
Teeth, Filling, etc., Johnson, 772. 
Tridymite, melting point, Ferguson 
and Merwin, 424. 


Utah, Green River desert section, 
Emery, 551. ; 

V ‘ 

Van Name, R. G., preparation of 
hypophosphates, 587. 

Vertebrz, Evolution of, Williston, 
546. 

Villavecchia, V., Chemistry, 765. 


WwW 
Warner, A. R., Dispensaries, 771. 
Wells, H. L., progress of chemis- 
try, 1818-1918, 250. 
West Virginia, coal beds, Hennen, 
770. 
geol. survey, 760, 770. 
Whetzel, H. H., Phytopathology, 
549. 


White, W. P., switch for delicate 
potential measurements, 610. 

Wieland, G. R., American fossil 
cycads, part VIII, 645. 

Williams, H. S., obituary notice, 
Schuchert, 682. 

Winchell, A. N., dustfall of March 
9, 1918, 599. 

Woodhouse, James, Life of, E. F. 
Smith, 541. 

Woodruff, L. L., Origin of Life, 770. 


».4 
X-Rays, absorption in aluminum, 
Williams, 766. 


Y 
Young, C. A., Astronomy, 542. 
Young, S., Stoichiometry, 689. 


Z 
Zinc Industry, Smith, 680. 
Zoology in America, 1818-1918, Coe, 
355: 


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